{"title":"Dual \/ Multi-Band Filters (Color)","description":null,"products":[{"product_id":"william-optics-stc-astro-duo-narrowband-filter","title":"William Optics STC Astro Duo-Narrowband Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual-Bandpass for H-Alpha and Oxygen-III\u003c\/li\u003e\n\u003cli\u003eSuppresses Urban Light Pollution\u003c\/li\u003e\n\u003cli\u003eIon Beam-Assisted Deposition (IBAD) Coatings\u003c\/li\u003e\n\u003cli\u003eHigh Durability and Easy-to-Clean Optical Surfaces\u003c\/li\u003e\n\u003cli\u003eMatte Black Anodized, Teflon-Coated Anti-Flare Frame\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eWilliam Optics STC Astro Duo-Narrowband Filter\u003c\/h2\u003e\n\u003cp\u003eThe William Optics STC Astro Duo-Narrowband Filter is engineered to isolate the two most important emission lines for nebula photography, Hydrogen-alpha (Hα) and Oxygen-III (OIII), while aggressively blocking light pollution. By utilizing advanced Ion Beam-Assisted Deposition (IBAD) coatings, this filter delivers exceptional signal-to-noise ratio and maintains spectral stability through changing temperatures, ensuring consistent results from your light-polluted backyard.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe Duo-Narrowband Advantage: Isolating Hα and OIII Emission Lines\u003c\/h3\u003e\n\u003cp\u003eUnlike broadband filters that pass a wide swath of the spectrum, the STC Astro Duo-Narrowband Filter targets the specific wavelengths emitted by planetary and emission nebulae. This selective transmission dramatically increases contrast by rejecting sodium and mercury vapor light from city streetlights, as well as natural skyglow, darkening the background and making faint nebulosity stand out.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eIBAD Coatings: Durability and Spectral Stability\u003c\/h3\u003e\n\u003cp\u003eThe filter employs Ion Beam-Assisted Deposition (IBAD) coating technology, which creates an extremely dense, hard, and moisture-resistant optical surface. This process ensures the filter's bandpass characteristics will not shift due to changes in temperature or humidity during an imaging session—a critical factor for maintaining consistent color balance and data quality. The robust coatings also make the filter surface easier to clean without risk of damage.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eEngineered Frame: Anti-Reflection and Easy Handling\u003c\/h3\u003e\n\u003cp\u003eEvery component is designed to minimize artifacts. The filter's frame is constructed from matte black anodized aluminum to absorb stray light and prevent internal reflections that can cause halos around bright stars. A Teflon coating on the frame's edge ensures smooth installation and removal from a filter wheel or camera nosepiece, reducing the risk of binding or cross-threading.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDuo-Narrowband vs. Broadband LPR Filters: A Sharper Cut\u003c\/h3\u003e\n\u003cp\u003eWhile a standard Light Pollution Reduction (LPR) filter offers a modest improvement from the city, a duo-narrowband design like the STC represents a significant step up for imaging emission nebulae. Where a broadband LPR filter might pass a wide range of blue and red light, the STC filter's tight focus on just the Hα and OIII lines provides a much darker sky background. This makes it the superior choice for objects like the Orion Nebula (M42) or the Lagoon Nebula (M8), though less ideal for broadband targets like galaxies and reflection nebulae which emit light across the entire spectrum.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main advantage of the William Optics STC Astro Duo-Narrowband Filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIts primary advantage is isolating the key \u003cstrong\u003eH-alpha\u003c\/strong\u003e and \u003cstrong\u003eOIII\u003c\/strong\u003e wavelengths emitted by most nebulae. This allows you to capture high-contrast images from light-polluted urban and suburban locations by rejecting the specific wavelengths associated with artificial lighting.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the STC Duo-Narrowband Filter perform on the Orion Nebula (M42) from a city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt will perform exceptionally well. The Orion Nebula (M42) is rich in both Hydrogen-alpha and Oxygen-III emissions. The William Optics STC Astro Duo-Narrowband Filter will darken the light-polluted sky background, dramatically increasing the contrast and revealing faint, extended structures in the nebula that would otherwise be invisible from a city.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the STC Duo-Narrowband Filter suitable for imaging galaxies like Andromeda (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this is not the ideal filter for broadband targets like galaxies. Galaxies and reflection nebulae shine by reflecting starlight across the entire visible spectrum. Because the \u003cstrong\u003eWilliam Optics STC Astro Duo-Narrowband Filter\u003c\/strong\u003e blocks most of that spectrum, it will significantly dim the galaxy and produce poor results. A broadband LPR filter or unfiltered imaging from a dark site is better for galaxies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the IBAD coating on the STC Duo-Narrowband Filter improve my images?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eIon Beam-Assisted Deposition (IBAD)\u003c\/strong\u003e process creates a very stable coating. This prevents the filter's transmission bands from shifting with temperature or humidity changes throughout the night. This stability ensures you get consistent color data and performance from dusk till dawn, a crucial factor for long-exposure astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat makes the frame of the STC Duo-Narrowband Filter special?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe frame is designed to enhance image quality and usability. It features:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatte Black Anodizing:\u003c\/strong\u003e Absorbs stray light to prevent internal reflections and halos.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTeflon Coating:\u003c\/strong\u003e Allows for smooth, easy installation and removal from your imaging train without jamming.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the William Optics STC Duo-Narrowband Filter for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile technically possible, it is not recommended. Narrowband filters like this one block a tremendous amount of light, and the resulting image through an eyepiece would be extremely dim. These filters are designed specifically for the long exposures used in astrophotography with one-shot-color or monochrome cameras.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/william-optics-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eWilliam Optics 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"William Optics","offers":[{"title":"Default Title","offer_id":44967225590045,"sku":"WO-YF-STC-ADN","price":660.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/William-Optics-STC-Astro-Duo-Narrowband-Filter-YF-STC-ADN-1__15183.1596133266.1280.1280.jpg?v=1684339179"},{"product_id":"william-optics-stc-ultra-layer-astro-multispectra-filter-48mm","title":"William Optics STC Ultra Layer Astro Multispectra Filter - 48mm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e48mm (M48) Filter Size\u003c\/li\u003e\n\u003cli\u003eMulti-Bandpass Light Pollution Suppression\u003c\/li\u003e\n\u003cli\u003ePasses H-α, H-β, and OIII Emission Lines\u003c\/li\u003e\n\u003cli\u003eSchott B270 Optical Glass Substrate\u003c\/li\u003e\n\u003cli\u003eSTC Ultra-Layer IBAD Anti-Reflection Coatings\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eWilliam Optics STC Ultra Layer Astro Multispectra Filter - 48mm\u003c\/h2\u003e\n\u003cp\u003eThe 48mm William Optics STC Ultra Layer Astro Multispectra Filter is engineered to restore natural color and contrast to astrophotography by suppressing common mercury, sodium, and LED light pollution while transmitting crucial H-alpha, H-beta, and OIII nebula lines through its coated Schott B270 optical glass.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eRestoring Natural Color from Light-Polluted Skies\u003c\/h3\u003e\n\u003cp\u003eThis filter is designed as a direct response to the challenge of urban and suburban imaging. It isolates and blocks the most common sources of artificial skyglow—specifically mercury vapor, high-pressure sodium, and certain disruptive LED frequencies—that wash out faint deep-sky objects.\u003c\/p\u003e\n\u003cp\u003eBy removing the offending wavelengths, the STC Astro Multispectra filter darkens the sky background significantly. This allows you to use longer exposures from compromised locations, revealing faint nebulosity and galactic structure while preserving a natural color balance in stars and surrounding fields.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eHigh-Contrast Imaging of H-α, H-β, and OIII Targets\u003c\/h3\u003e\n\u003cp\u003eWhile aggressively filtering light pollution, the STC Astro Multispectra preserves the most important wavelengths for astrophotography. The filter's bandpass is tailored to transmit the deep red of Hydrogen-alpha, the teal of Oxygen-III, and the blue-green of Hydrogen-beta with high efficiency.\u003c\/p\u003e\n\u003cp\u003eThis selective transmission dramatically increases the contrast between emission nebulae and the background sky. Objects like the North American Nebula (NGC 7000) or the Orion Nebula (M42) stand out with enhanced structure and saturation, producing images with greater depth and clarity even from a backyard observatory.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSchott B270 Glass and Ion Beam Assisted Coatings\u003c\/h3\u003e\n\u003cp\u003eThe filter's optical foundation is premium Schott B270 glass, known for its clarity and homogeneity. This ensures that the filter imparts no degradation to your imaging system's resolution. Each surface is treated with STC’s proprietary Ultra Layer coatings applied via Ion Beam Assisted Deposition (IBAD).\u003c\/p\u003e\n\u003cp\u003eThis advanced coating process results in an exceptionally hard, durable, and environmentally stable surface that resists moisture and is easier to clean. The multi-layer coatings are also optimized to minimize reflections and prevent the halos around bright stars that can plague inferior filters, ensuring maximum light transmission of the desired wavelengths.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of light pollution does the WO STC Astro Multispectra filter block?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe filter is designed to suppress the most common sources of urban light pollution, including \u003cstrong\u003emercury vapor lamps\u003c\/strong\u003e, \u003cstrong\u003ehigh and low-pressure sodium vapor lamps\u003c\/strong\u003e, and certain wavelengths of \u003cstrong\u003eLED lighting\u003c\/strong\u003e that cause skyglow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 48mm STC Astro Multispectra filter good for imaging galaxies like Andromeda (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it is very effective for broadband targets like galaxies. By reducing skyglow, the filter increases the contrast between the galaxy's faint outer arms and the night sky. Unlike narrowband filters, it preserves the natural star colors in the galaxy's halo and core, making it an excellent choice for imaging M31 from suburban locations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the STC Astro Multispectra filter affect star color compared to a UHC filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe STC Astro Multispectra is designed to produce more \u003cstrong\u003enatural star colors\u003c\/strong\u003e. While a traditional UHC (Ultra High Contrast) filter creates very high contrast on nebulae, it often does so at the cost of a strong blue-green color cast. This filter uses a multi-bandpass approach to let more of the stellar continuum through, resulting in a more balanced and photographically neutral image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the STC Astro Multispectra 48mm filter with a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the \u003cstrong\u003e48mm (or 2-inch) filter size\u003c\/strong\u003e is ideal for use with full-frame DSLR or dedicated astronomy cameras. The large format prevents vignetting, ensuring the sensor is evenly illuminated from corner to corner, which is critical for wide-field astrophotography and Milky Way landscapes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat makes the IBAD coatings on this filter special?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eIon Beam Assisted Deposition (IBAD)\u003c\/strong\u003e is an advanced coating process that creates extremely dense and durable layers on the optical surface. This makes the filter's coatings highly resistant to scratching from routine cleaning and degradation from environmental factors like humidity. It also yields superior anti-reflection performance, preventing halos and internal reflections.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs this filter suitable for imaging large targets like the North American Nebula (NGC 7000)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. This filter is perfect for large, emission-rich targets like the North American Nebula (NGC 7000) or the Veil Nebula complex. It allows the critical \u003cstrong\u003eH-alpha and OIII\u003c\/strong\u003e light from the nebula to pass through while blocking skyglow, making it ideal for capturing these objects with wide-field refractors or camera lenses.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eAstro Multispectra Light Pollution\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e48mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThread\u003c\/td\u003e\n\u003ctd\u003eM48\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGlass Substrate\u003c\/td\u003e\n\u003ctd\u003eSchott B270\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoating Technology\u003c\/td\u003e\n\u003ctd\u003eSTC Ultra Layer IBAD\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eWilliam Optics STC Ultra Layer Astro Multispectra Filter - 48mm\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/william-optics-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eWilliam Optics 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"William Optics","offers":[{"title":"Default Title","offer_id":44967226573085,"sku":"WO-YF-STC-M48","price":328.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/William-Optics-STC-Ultra-Layer-Astro-Multispectra-Filter-48mm-YF-STC-M48-1__78203.1596133266.1280.1280.jpg?v=1684339482"},{"product_id":"zwo-duo-band-filter","title":"ZWO Duo-Band Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003ePasses H-Alpha (15nm) and OIII (35nm) Wavelengths\u003c\/li\u003e\n\u003cli\u003eDesigned for One-Shot Color (OSC) Cameras\u003c\/li\u003e\n\u003cli\u003e1.25\" Threaded Cell\u003c\/li\u003e\n\u003cli\u003eOver 80% Ha \u0026amp; 90% OIII Transmission\u003c\/li\u003e\n\u003cli\u003e1\/4 Wavefront Polished Substrate\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eZWO 1.25\" Duo-Band Filter\u003c\/h2\u003e\n\u003cp\u003eThe ZWO 1.25\" Duo-Band Filter makes narrowband imaging possible for color cameras by isolating the two most critical emission nebula wavelengths. It captures H-Alpha (656.3 nm) in a 15 nm bandpass and OIII (500 nm) in a 35 nm bandpass, with transmission rates exceeding 80% and 90% respectively. This dual-band approach dramatically increases contrast on emission targets, allowing you to capture clean, detailed data from light-polluted locations with your existing one-shot color camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eCapture Narrowband Data with Your OSC Camera at Over 90% Transmission\u003c\/h3\u003e\n\u003cp\u003eThis filter is the most direct path to narrowband imaging for any astronomer with a color CMOS or CCD camera. By simultaneously passing both the deep red of Hydrogen-alpha and the teal-blue of Oxygen-III, it collects the primary structural and detail wavelengths of emission nebulae in a single exposure. This eliminates the need for a monochrome camera, filter wheel, and separate SHO filter set, significantly simplifying your imaging train and reducing total acquisition time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e15nm Ha \u0026amp; 35nm OIII Bandpasses Optimized for Signal\u003c\/h3\u003e\n\u003cp\u003eThe ZWO Duo-Band filter features a 15 nm bandpass for H-Alpha and a wider 35 nm bandpass for OIII. This design is a deliberate trade-off, balancing interference rejection with the signal requirements of a color sensor's Bayer matrix. These wider-than-typical bandpasses allow more photons to reach the sensor, which is critical for achieving a strong signal-to-noise ratio with an OSC camera in reasonable exposure times, while still blocking the vast majority of light pollution from city lights and moonlight.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eZWO Duo-Band Filter vs. A Full Monochrome Setup\u003c\/h3\u003e\n\u003cp\u003eA dedicated monochrome camera with a filter wheel and 3nm or 5nm narrowband filters will always provide the highest possible resolution and data separation. That setup allows for precise control over each channel for complex Hubble Palette (SHO) processing. However, the ZWO Duo-Band Filter with a color camera grants access to high-contrast nebula imaging at a fraction of the cost, complexity, and setup time. For imagers in light-polluted skies who want to capture stunning nebulae without investing in a second complete imaging system, the Duo-Band filter is the more pragmatic solution.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e1\/4 Wavefront Optics \u0026amp; Anti-Reflection Build\u003c\/h3\u003e\n\u003cp\u003eEach Duo-Band filter is built on a Schott substrate, polished to a 1\/4 wavefront accuracy to ensure your telescope's resolution is not compromised. The 60\/40 surface quality meets MIL-O-13830 standards, and the filter cell itself is CNC machined from aircraft-grade aluminum. An anodized finish and internal extinction treatments prevent reflections and internal glare from degrading your final image, preserving the high contrast this filter is designed to create.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the ZWO Duo-Band Filter perform on the Orion Nebula (M42) with a color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO Duo-Band filter is excellent for the Orion Nebula (M42). It will isolate the rich Hydrogen-alpha signal in the outer wings and the strong Oxygen-III emission in the Trapezium core. From a light-polluted site, this filter will dramatically darken the sky background, making the nebula's structure and color far more prominent than with a standard light pollution filter.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I image galaxies like Andromeda (M31) with the ZWO Duo-Band Filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this filter is not recommended for broadband targets like galaxies or star clusters. Galaxies emit light across the entire visible spectrum. The Duo-Band filter blocks almost all of that light, passing only the H-alpha and OIII wavelengths. While you would capture the small emission nebulae within M31's arms, the galaxy's core and dust lanes would be almost completely filtered out. Use a broadband light pollution filter for galaxies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy are the H-Alpha (15nm) and OIII (35nm) bandpasses different widths on the ZWO Duo-Band Filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe different bandpass widths are an intentional design choice for use with one-shot color cameras. The wider \u003cstrong\u003e35 nm OIII bandpass\u003c\/strong\u003e allows more signal to pass through the Bayer matrix of the sensor, which is less sensitive to these wavelengths. The tighter \u003cstrong\u003e15 nm Ha bandpass\u003c\/strong\u003e provides higher contrast on the stronger hydrogen signal, balancing signal strength with rejection of nearby light pollution sources.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ZWO Duo-Band Filter a good replacement for a monochrome camera setup?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt is an excellent alternative, but not a direct replacement. A monochrome camera with separate, very narrowband (e.g., 3nm) filters offers superior data isolation for advanced processing techniques like the Hubble Palette. The ZWO Duo-Band Filter provides a much simpler and more affordable way for OSC camera users to achieve the high-contrast results of narrowband imaging on emission nebulae, without the cost and complexity of a full mono system.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 1.25\" ZWO Duo-Band filter work in my ZWO EFW filter wheel?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the ZWO 1.25\" Duo-Band Filter is threaded to mount directly into any ZWO electronic filter wheel (EFW) that accepts 1.25\" filters. It can also be threaded directly onto any 1.25\" nosepiece or accessory with standard filter threads.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the 60\/40 surface quality specification mean for the ZWO Duo-Band Filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis specification refers to the optical polish and surface imperfections based on the MIL-O-13830 military standard. The \"60\" is the scratch designation, nominally corresponding to a scratch width of about 6 microns, and the \"40\" refers to the maximum allowable dig or pit diameter in hundredths of a millimeter. A 60\/40 rating indicates a high-quality optical surface suitable for demanding imaging applications, ensuring minimal light scatter and preserved image contrast.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-DB1.25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eDual Narrowband Pass (Ha, OIII)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e1.25\" (31.75mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eThreaded Cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eH-Alpha Bandpass\u003c\/td\u003e\n\u003ctd\u003e15 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOIII Bandpass\u003c\/td\u003e\n\u003ctd\u003e35 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eH-Alpha Transmission\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;80% at 656.3 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOIII Transmission\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;90% at 495.9 nm and 500.7 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWavefront Accuracy\u003c\/td\u003e\n\u003ctd\u003e1\/4 Wavefront\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate\u003c\/td\u003e\n\u003ctd\u003eSchott Glass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThickness\u003c\/td\u003e\n\u003ctd\u003e1.85 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40 (per MIL-O-13830)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShape\u003c\/td\u003e\n\u003ctd\u003eRound\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eZWO 1.25\" Duo-Band Filter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.zwoastro.com\/software\/\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"1.25\" Round Mounted","offer_id":44967448379677,"sku":"ZWO-DB1.25","price":139.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":44967448412445,"sku":"ZWO-DB2","price":239.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/ZWO-Duo-Band-Filter-1__12335.1596910054.1280.1280.jpg?v=1684342173"},{"product_id":"optolong-l-enhance-filter","title":"Optolong L-Enhance Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual-bandpass filter isolates H-Alpha, H-Beta, and OIII emission lines\u003c\/li\u003e\n\u003cli\u003ePeak transmission of over 90% for maximum signal\u003c\/li\u003e\n\u003cli\u003eBlocks over 99% of light pollution across a 300-1000nm range\u003c\/li\u003e\n\u003cli\u003eMaintains image sharpness with a λ\/4 transmitted wavefront\u003c\/li\u003e\n\u003cli\u003eConstructed from 1.85mm thick B270 optical glass\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eOptolong L-Enhance Filter\u003c\/h2\u003e\n\u003cp\u003eThe Optolong L-Enhance filter is an economical, high-transmission solution for color astrophotography from light-polluted skies. This dual-bandpass filter achieves over 90% peak transmission in the critical H-Alpha, H-Beta, and Oxygen III emission lines, capturing the most important nebula data with any color camera. It simultaneously eliminates the impact of urban skyglow by blocking more than 99% of light pollution lines across a wide 300-1000nm range. The entire optical path is built on a 1.85mm B270 substrate polished to a λ\/4 transmitted wavefront, ensuring your telescope's resolution is perfectly preserved.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDual-Bandpass Design: Over 90% Transmission in H-Alpha, H-Beta \u0026amp; OIII\u003c\/h3\u003e\n\u003cp\u003eUnlike broadband filters that pass large sections of the spectrum, the L-Enhance isolates only the most important wavelengths for emission nebulae. By targeting H-Alpha (656nm), H-Beta (486nm), and OIII (500nm) with a peak transmission greater than 90%, it dramatically increases the contrast between your target and the sky background. This design choice prioritizes the wavelengths associated with hydrogen and oxygen—the building blocks of star formation—to deliver scientifically significant data from your color camera in a single shot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eLight Pollution Suppression: \u0026gt;99% Rejection of Unwanted City Glow\u003c\/h3\u003e\n\u003cp\u003eFor imagers in urban or suburban locations, the primary challenge is skyglow from artificial lighting. The L-Enhance filter meets this challenge with an aggressive blocking depth of over 99% for major light pollution sources, including mercury and sodium vapor lamps. This deep blocking darkens the sky background in your images, allowing the faint, desirable light from nebulae to stand out clearly. The result is longer possible sub-exposure times and a signal-to-noise ratio that was previously only achievable from dark sites.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOptical \u0026amp; Build Quality: λ\/4 Wavefront on a 1.85mm B270 Substrate\u003c\/h3\u003e\n\u003cp\u003eA filter should only transmit light, not distort it. The Optolong L-Enhance is built on a 1.85mm thick B270 glass substrate, polished to a surface quality of 60\/40 and a parallelism of 30 arcseconds. Critically, it guarantees a transmitted wavefront of λ\/4 or better, ensuring that it will not introduce aberrations or degrade the sharp stars produced by your telescope's optics. Advanced ion-assisted deposition coatings ensure these transmission characteristics are durable, scratch-resistant, and stable regardless of temperature changes during an imaging session.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe 1-Shot-Color Solution: L-Enhance vs. Monochrome Narrowband\u003c\/h3\u003e\n\u003cp\u003eWhile a monochrome camera with a filter wheel and separate S-II, H-Alpha, and O-III filters offers maximum data control, this approach is complex and expensive. The Optolong L-Enhance provides a streamlined and highly effective alternative for one-shot-color (OSC) cameras like DSLRs and dedicated astronomy CMOS cameras.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eEfficiency:\u003c\/strong\u003e The L-Enhance captures two of the most important bandpasses (H-Alpha and OIII) simultaneously, dramatically reducing the total imaging time required compared to shooting each channel separately with a mono camera.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSimplicity:\u003c\/strong\u003e It eliminates the need for a filter wheel and the complexities of combining multiple monochrome datasets, making deep-sky imaging more accessible.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCost-Effectiveness:\u003c\/strong\u003e For a fraction of the cost of a full monochrome setup, the L-Enhance unlocks the ability to shoot high-contrast nebula images from the city.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat makes the Optolong L-Enhance different from a standard light pollution filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA standard light pollution (LPS) filter is a \u003cstrong\u003ebroadband\u003c\/strong\u003e filter that tries to notch out specific light pollution lines while passing most other light. The Optolong L-Enhance is a \u003cstrong\u003emulti-bandpass narrowband\u003c\/strong\u003e filter. It works in reverse: it blocks almost the entire spectrum, only passing specific, narrow bands corresponding to nebula emission lines (H-Alpha, H-Beta, and OIII), resulting in much higher contrast.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong L-Enhance filter with a monochrome camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, you can. While designed for color cameras, the L-Enhance works well with a monochrome camera to capture H-Alpha, H-Beta, and OIII data simultaneously for a high-quality luminance frame. This is useful for simplifying data acquisition, though you will not be able to separate the individual channels for color mapping as you would with dedicated single-bandpass filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Optolong L-Enhance perform on a target like the North America Nebula (NGC 7000) from the suburbs?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Optolong L-Enhance is exceptionally effective on emission nebulae like the North America Nebula (NGC 7000) and the nearby Pelican Nebula (IC 5070). These targets are rich in Hydrogen-Alpha, which the filter passes with over 90% transmission. From a suburban location, the filter's \u0026gt;99% blocking of skyglow will darken the background, revealing the intricate structures and faint extensions of the nebula that would otherwise be lost.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong L-Enhance effective for imaging the Veil Nebula complex under moonlight?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. Moonlight is broadband light, and a narrowband filter like the L-Enhance is the best tool for mitigating its effects. Because the filter only passes the narrow bands of OIII and H-Alpha\/H-Beta, it blocks the vast majority of moonlight. This allows you to continue imaging targets rich in those emissions, like the Veil Nebula, even during bright moonlit nights.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy does the Optolong L-Enhance pass H-Beta in addition to H-Alpha and OIII?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe H-Beta emission line (486nm) is very close to the OIII lines (~500nm). The L-Enhance is designed with a wider bandpass in the blue-green part of the spectrum that includes both OIII and H-Beta. This captures more signal from objects that have strong H-Beta emission, such as the California Nebula or Horsehead Nebula, adding to the richness of the final image from a color camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill I need to refocus when using the 1.85mm Optolong L-Enhance filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, adding any filter into the optical path will shift the focus point. The 1.85mm thickness of the B270 glass will require a small amount of outward focus travel. It is always recommended to check and readjust focus after inserting or removing a filter.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Material\u003c\/td\u003e\n\u003ctd\u003eB270\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e1.85mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmission\u003c\/td\u003e\n\u003ctd\u003eT\u0026gt;90%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e300-1000nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Depth\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;99% at light pollution lines\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmitted Wavefront\u003c\/td\u003e\n\u003ctd\u003eλ\/4 RMS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable Sizes\u003c\/td\u003e\n\u003ctd\u003e1.25\" Mounted, 2\" Mounted, Clip for Canon EOS APS-C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/optolong-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eOptolong 3-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Optolong","offers":[{"title":"1.25\" Mounted","offer_id":44967781531933,"sku":"OPT-13801","price":251.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Mounted","offer_id":44967781564701,"sku":"OPT-13802","price":321.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Canon EOS APS-C","offer_id":44967781597469,"sku":"OPT-13804","price":363.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Optolong-L-Enhance-2inch__85261.1612894707.1280.1280.jpg?v=1684345842"},{"product_id":"optolong-l-extreme-filter","title":"Optolong L-Extreme Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eNarrow dual-bandpass filter for H-Alpha and OIII\u003c\/li\u003e\n\u003cli\u003eBlocks \u0026gt;99% of light pollution emission lines\u003c\/li\u003e\n\u003cli\u003ePeak transmission of \u0026gt;90% at critical wavelengths\u003c\/li\u003e\n\u003cli\u003eTransmitted Wavefront RMS of λ\/4\u003c\/li\u003e\n\u003cli\u003e1.85mm thick B270 substrate with 30s parallelism\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eOptolong L-Extreme Filter\u003c\/h2\u003e\n\u003cp\u003eThe Optolong L-Extreme Filter isolates critical nebula emission lines with over 90% peak transmission while blocking more than 99% of common light pollution sources. Built on a 1.85mm B270 substrate, its λ\/4 transmitted wavefront and 30s parallelism ensure your optical system's native resolution is maintained. This narrow dual-band design simultaneously captures H-alpha and Oxygen III, maximizing contrast for one-shot color and monochrome cameras operating under bright urban skies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA Dual-Band Design for \u0026gt;99% Light Pollution Suppression\u003c\/h3\u003e\n\u003cp\u003eThe L-eXtreme isolates the two most important emission lines for most nebulae—Hydrogen-alpha and Oxygen III—on a single filter. By aggressively blocking wavelengths outside these passbands, including a \u0026gt;99% rejection of artificial light pollution, the filter produces a dramatic increase in contrast between your target and the skyglow background. This allows you to capture clean, detailed data even from severely light-polluted locations or during bright moonlit nights.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOptimized for Fast Optics and One-Shot Color Cameras\u003c\/h3\u003e\n\u003cp\u003eModern fast optical systems, such as f\/2 RASA or HyperStar setups, place high demands on filter performance. The L-eXtreme is engineered to minimize band-shift with these steep light cones, ensuring consistent transmission and color balance. For imagers using one-shot color cameras like DSLRs or dedicated CMOS astronomy cameras, this filter is a cost-effective and convenient way to produce detailed bicolor images without the need for a filter wheel and monochrome setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eλ\/4 Wavefront Accuracy and Durable Ion-Assisted Coatings\u003c\/h3\u003e\n\u003cp\u003eA filter should never degrade the quality of your telescope's optics. The L-eXtreme is manufactured to strict tolerances, with a transmitted wavefront of λ\/4 and parallelism of 30 arcseconds, preventing any introduction of aberrations or distorted star shapes. The multi-layer coatings are applied using an advanced ion-assisted deposition process, creating a durable, scratch-resistant surface that provides wavelength stability regardless of temperature changes during an imaging session.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOptolong L-eXtreme vs. L-eNhance: The Tri-Band Trade-Off\u003c\/h3\u003e\n\u003cp\u003eThe primary difference lies in their bandpass strategy. The L-eNhance is a tri-band filter, passing H-alpha, OIII, and H-beta. The L-eXtreme is a dual-band filter, passing only H-alpha and OIII.\u003c\/p\u003e\n\u003cp\u003eThe L-eXtreme's advantage is its complete rejection of the wavelengths between the H-beta and OIII lines. This region contains no significant nebula emission but is a source of urban light pollution. By blocking it, the L-eXtreme delivers a darker sky background and higher overall contrast on most targets, making it the superior choice for maximum signal-to-noise ratio in heavy light pollution.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat makes the Optolong L-eXtreme different from the L-eNhance filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eOptolong L-eXtreme\u003c\/strong\u003e is a dual-band filter that isolates the H-alpha and OIII emission lines. The L-eNhance is a tri-band filter that also includes H-beta. The L-eXtreme provides higher contrast and darker skies by blocking the light pollution between the H-beta and OIII lines, a region with no major nebula emissions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong L-eXtreme filter with my DSLR camera in the city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. The L-eXtreme is designed specifically for this purpose. It works exceptionally well with one-shot color cameras like DSLRs and dedicated astronomy cameras, allowing you to capture high-contrast images of emission nebulae despite heavy urban light pollution.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Optolong L-eXtreme perform on the Orion Nebula (M42) from a light-polluted suburb?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe L-eXtreme is an excellent choice for the Orion Nebula (M42). It will dramatically darken the sky background, enhancing the faint, extended nebulosity while preserving the natural colors of the hydrogen (red) and oxygen (teal) regions. You will be able to capture significantly more detail in the nebula's structure than you could without a filter.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong L-eXtreme suitable for fast telescopes like a RASA or HyperStar system?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the L-eXtreme is well-suited for fast optical systems. Its coatings are designed to minimize the band-shift effects that can occur with steep light cones (low f-ratios), ensuring reliable performance and color balance even at f\/2.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the L-eXtreme filter work for monochrome cameras?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile designed with one-shot color cameras in mind, the L-eXtreme can be used effectively with monochrome cameras. It allows you to capture H-alpha and OIII data simultaneously. For serious monochrome imaging, separate narrowband filters for Ha, OIII, and SII will offer more control, but the L-eXtreme provides a convenient way to gather data for a bicolor Hubble-palette style image in less time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy doesn't the Optolong L-eXtreme pass H-beta light?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis is a deliberate design choice to maximize contrast. While a few nebulae, like the Horsehead Nebula (Barnard 33), have a notable H-beta signal, most emission nebulae are dominated by H-alpha and OIII. By blocking the H-beta line and the region between it and OIII, the L-eXtreme eliminates more light pollution, leading to a better signal-to-noise ratio on the vast majority of targets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate\u003c\/td\u003e\n\u003ctd\u003eB270\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThickness\u003c\/td\u003e\n\u003ctd\u003e1.85mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmission\u003c\/td\u003e\n\u003ctd\u003eT\u0026gt;90%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e300-1000nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Depth\u003c\/td\u003e\n\u003ctd\u003eLight pollution line blocking \u0026gt;99%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmitted Wavefront RMS\u003c\/td\u003e\n\u003ctd\u003eλ\/4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable Sizes\u003c\/td\u003e\n\u003ctd\u003e1.25\" Mounted, 2\" Mounted\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/optolong-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eOptolong 3-Year Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Optolong","offers":[{"title":"1.25\" Mounted","offer_id":44967910277405,"sku":"OPT-13901","price":335.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Mounted","offer_id":44967910310173,"sku":"OPT-13902","price":432.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Nikon Z Full Frame","offer_id":52942348550429,"sku":"OPT-LEXTREME-NK-Z","price":363.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Optolong-L-Enhance__74495.1625788241.1280.1280.jpg?v=1684346873"},{"product_id":"optolong-l-ultimate-filter","title":"Optolong L-Ultimate Ha\/OIII 3nm Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual 3nm bandpass isolates Hydrogen-alpha and Oxygen-III emission lines\u003c\/li\u003e\n\u003cli\u003eBlocks light pollution across the 300-1000nm spectrum\u003c\/li\u003e\n\u003cli\u003eGreater than OD4 blocking of unwanted wavelengths\u003c\/li\u003e\n\u003cli\u003eλ\/4 transmitted wavefront for sharp, high-resolution images\u003c\/li\u003e\n\u003cli\u003ePrecision 60\/40 surface quality optical glass substrate\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eOptolong L-Ultimate Ha\/OIII 3nm Filter\u003c\/h2\u003e\n\u003cp\u003eThe Optolong L-Ultimate Ha\/OIII 3nm Filter isolates critical nebula emission lines with an extremely narrow 3nm full width at half maximum (FWHM) for both its H-alpha and OIII channels. This filter achieves its deep-sky contrast by implementing greater than OD4 blocking across a wide 300-1000nm range, effectively eliminating light pollution from urban and suburban skies. Each filter is manufactured to a λ\/4 transmitted wavefront standard, ensuring that the filter itself does not degrade the resolution of your optical system.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDual 3nm Bandpass for Maximum Nebula Contrast\u003c\/h3\u003e\n\u003cp\u003eBy restricting the incoming light to only the H-alpha (656nm) and OIII (500nm) emission lines within a tight 3nm window, the L-Ultimate filter dramatically increases the signal-to-noise ratio of emission nebulae. This surgical isolation means that the faint, intricate structures within targets like the Squid Nebula (OU4) or supernova remnants are captured with stark contrast against a near-black sky background. The result is an image with significantly more \"pop\" and detail compared to what is possible with broader-band filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e\u0026gt;OD4 Blocking for Urban Imaging\u003c\/h3\u003e\n\u003cp\u003eFor astrophotographers working under light-polluted skies, the L-Ultimate's primary function is its aggressive rejection of unwanted artificial and natural light. With a blocking efficiency rated at an optical density greater than 4 (\u0026gt;OD4), it effectively nullifies the glow from mercury vapor, high and low-pressure sodium streetlights, and the natural atmospheric airglow. This level of suppression allows you to capture clean, long-exposure data from even the most challenging urban environments, turning previously unfruitful nights into productive imaging sessions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eλ\/4 Optics and Advanced Ion Coatings\u003c\/h3\u003e\n\u003cp\u003eOptolong builds the L-Ultimate filter on an optical glass substrate polished to a 60\/40 surface quality and a transmitted wavefront of λ\/4, preserving the sharpness of your telescope's optics. The filter's dielectric coatings are applied using an advanced ion-assisted deposition process, which creates a durable, scratch-resistant surface. This modern coating technique also ensures the central wavelength of the bandpass remains stable and does not drift with temperature changes, providing consistent results from night to night.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eL-Ultimate vs. L-eXtreme \u0026amp; L-eNhance: Why 3nm Matters\u003c\/h3\u003e\n\u003cp\u003eWhile filters like the Optolong L-eXtreme and L-eNhance are effective dual-band filters, the L-Ultimate distinguishes itself with its much narrower 3nm bandpasses. This tighter specification provides several key advantages for specific imaging goals.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDarker Sky Background:\u003c\/strong\u003e The 3nm window passes less of the skyglow continuum and blocks more of the light from stars, leading to a darker overall background and enhanced nebula contrast.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBetter Star Suppression:\u003c\/strong\u003e By collecting less stellar light outside the core emission lines, stars appear smaller and less prominent, allowing the faint nebulosity to dominate the image.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTrade-Off:\u003c\/strong\u003e The primary limitation is that its tight bandpass is not well-suited for very fast optical systems (typically f\/4 and faster), where significant band-shift can occur. For these systems, a broader filter like the L-eXtreme may be more appropriate.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main difference between the Optolong L-Ultimate and the L-eXtreme filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary difference is the bandpass width. The \u003cstrong\u003eL-Ultimate uses a very narrow 3nm bandpass\u003c\/strong\u003e for both H-alpha and OIII, while the L-eXtreme uses a wider 7nm bandpass. The L-Ultimate's 3nm design provides a darker sky background and better star control, maximizing contrast on emission nebulae, but it is less suited for very fast telescopes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong L-Ultimate filter with a DSLR or a color astronomy camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the L-Ultimate is specifically designed for use with one-shot color cameras like DSLRs and dedicated color CMOS\/CCD cameras. It passes both the red H-alpha and blue-green OIII light simultaneously, allowing you to capture a detailed, color-rich image of emission nebulae in a single set of exposures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is the Optolong L-Ultimate not recommended for fast telescopes (f\/4 and faster)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eExtremely narrow filters like the L-Ultimate can experience \"band-shift\" when used with fast optical systems. The steep light cone from a fast telescope causes the filter's central wavelength to shift away from the intended emission line for off-axis light rays. This can result in a loss of signal. For telescopes f\/4 or faster, a filter with a slightly wider bandpass, like 7nm, is often a better choice to avoid this effect.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Optolong L-Ultimate perform on a target like the Veil Nebula (NGC 6960) from a city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe L-Ultimate is ideal for this scenario. The Veil Nebula is rich in both H-alpha and OIII, and the filter's dual 3nm bandpasses will isolate this signal while its \u0026gt;OD4 blocking rejects the city light pollution. You can expect to capture the delicate, filamentary structure of the nebula with high contrast against a dark background, even from a heavily light-polluted site.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong L-Ultimate a good choice for my 8\" f\/10 SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, an f\/10 Schmidt-Cassegrain Telescope is an excellent match for the L-Ultimate filter. Slower optical systems like SCTs do not cause the band-shift issues seen in fast refractors or Newtonians. The filter will work at its peak efficiency, delivering maximum contrast and light pollution suppression for imaging emission nebulae.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Optolong L-Ultimate filter work on galaxies or reflection nebulae?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this filter is not designed for broadband targets. Galaxies like Andromeda (M31) and reflection nebulae like the Pleiades (M45) shine by reflecting starlight across the entire visible spectrum. The L-Ultimate blocks almost all of this light, so these objects would be rendered extremely faint or invisible. It is exclusively for emission nebulae that glow at the specific H-alpha and OIII wavelengths.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFWHM\u003c\/td\u003e\n\u003ctd\u003eOIII 3nm, H-alpha 3nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate\u003c\/td\u003e\n\u003ctd\u003eOptical Glass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e300-1000nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Efficiency\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmitted Wavefront RMS\u003c\/td\u003e\n\u003ctd\u003eλ\/4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30 arcseconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable Sizes\u003c\/td\u003e\n\u003ctd\u003e1.25\" Mounted, 2\" Mounted\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eOptolong L-Ultimate Ha\/OIII 3nm Filter with Protective Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/optolong-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eOptolong 3-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Optolong","offers":[{"title":"1.25\" Mounted","offer_id":50286466203933,"sku":"OPT-11601","price":404.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Mounted","offer_id":44968046559517,"sku":"OPT-11602","price":545.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Optolong-L-Ultimate-2-inch-2__17268.1665168471.1280.1280.jpg?v=1684348283"},{"product_id":"antlia-triband-rgb-ultra-filter","title":"Antlia Triband RGB Ultra Filter V2","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eEnhanced Transmission for Superior Signal-to-Noise Ratio\u003c\/li\u003e\n\u003cli\u003eAnti-Reflection Coating to Reduce Halo Effect\u003c\/li\u003e\n\u003cli\u003eOptimized for Fast Optics up to f\/2\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003c!-- Title image text --\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003c!-- Main Image --\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAntlia Triband RGB Ultra Filter V2 - Overview\u003c\/h2\u003e\n\u003cimg class=\"DAV-img-banner\" alt=\"Antlia Triband RGB Ultra Filter V2\" src=\"https:\/\/davidastro.com\/cdn\/shop\/products\/ANT-TRI-RGB-2__19119.1677769060.1280.1280_936x936.jpg\"\u003e\n\u003cp\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- Features Grid --\u003e\n\u003cdiv class=\"DAV-feature-grid\"\u003e\n\u003c!-- Feature Box 1 --\u003e\n\u003cdiv class=\"DAV-feature-box\"\u003e\n\u003ch3\u003eHigh Signal-to-Noise Ratio\u003c\/h3\u003e\n\u003cp\u003eSuperior imaging in challenging light conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!-- Feature Box 2 --\u003e\n\u003cdiv class=\"DAV-feature-box\"\u003e\n\u003ch3\u003eVersatile Applications\u003c\/h3\u003e\n\u003cp\u003eDesigned for light pollution suppression for OSC and Mono cameras.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!-- Feature Box 3 --\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-section-container\"\u003e\n\u003cdiv class=\"DAV-section-text\"\u003e\n\u003ch3\u003eAntlia Triband RGB Ultra Filter V2 Filter\u003c\/h3\u003e\n\u003cp\u003eIt is designed for light pollution suppression for OSC and Mono cameras. The spectral design selected the most substantial information in the RGB bands, which makes Antlia Triband RGB Ultra Filter possible to shoot over 90% of deep sky objects, in addition to its excellent performance on emission nebula, different from other ultra-narrowband filters, it is able to capture galaxies, reflection nebulae, and star clusters from a Bortle 8 location to Bortle 1 while presenting more balanced RGB colors in your images. Also, it has a broad bandpass designed to cope with faster optics up to the f\/2 focal ratio. \u003cbr\u003eThe quantum efficiency of the B channel in current CMOS sensors is often significantly lower than that of R and G channels. Antlia team was to provide a filter with a more realistic color balance for astrophotography from light polluted locations. The problem with the low blue wavelength efficiency becomes apparent when imaging reflection nebulae and blue stars. In CMOS sensors, the blue wavelengths also contain contribution from the stronger green spectrum, thereby affecting the balance of the blue colours. Many popular imaging objects contain reflection nebula with faint blue hues such the central part ofNGC2264. Therefore, we designed Antlia Triband RGB Ultra Filter that not only retains the HSO emission signal but alsoincreases the amount of Luminous flux of the blue B channel. By improving the blue wavelength transmission, the color of thephoto is better balanced and easier to manage in post processing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-section-img\"\u003e\u003cimg alt=\"Sii\u0026amp;Hb\" src=\"https:\/\/davidastro.com\/cdn\/shop\/products\/ANT-TRI-RGB-2__19119.1677769060.1280.1280_936x936.jpg\"\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ch2\u003eSII\u0026amp;Hβ 3.5nm Filter\u003c\/h2\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003eFWHM\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003e3.5mm\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003ePeak Transmission\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003e92% (Ha), 92% (Sii), 92% (Oiii), 92% (Nii)\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003eBlocking\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003e≥ OD4 (300-1100nm)\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003eRing Design\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003eUltra-thin and black anodized to minimize reflections\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cimg class=\"DAV-img-box\" alt=\"HaOIII\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAntlia Triband RGB Ultra Filter V2 Filter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Antlia","offers":[{"title":"2\" Mounted","offer_id":44968075231517,"sku":"ANT-TRIBAND-V2","price":254.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/ANT-TRI-RGB-2__19119.1677769060.1280.1280.jpg?v=1684348732"},{"product_id":"antlia-alp-t-dualband-5nm-sii-hb-filter","title":"Antlia ALP-T Dualband 5nm SII\/Hb Filter","description":"\u003c!-- more --\u003e\n\u003cp\u003e\u003cspan\u003eThe ALP-T dual band 5nm SII\u0026amp;Hb \u003c\/span\u003e\u003cspan\u003ef\u003c\/span\u003e\u003cspan\u003eilter is a dual line-pass filter, which lets the deep red \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eSulfur-II\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e line and the blue \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eHydrogen-Beta\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e line through and is used with one-shot color (OSC) cameras such as DSLR's or astronomical OSC cameras. It is a significant addition to the popular Antlia ALP-T dual band 5nm Ha\u0026amp;OIII filter and enables false-color images and narrow-band nebula images using OSC. When capturing data with this filter, the nebulae are recorded with greater contrast against the background than without it.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe\u003c\/span\u003e\u003cspan\u003e combination of these two dual band filters allows extreme narrow-band images with OSC cameras by capturing the spectral data from 4 channels i.e. Ha\/OIII\/SII\/Hb. The spectrum of these four channels can be separated and recombined into various colour palettes in your post-processing. The resulting images can be used for luminance contrast enhancement of traditional RGB-balanced images or creation of images in various popular false-color palettes such as \u003c\/span\u003e\u003cspan\u003eH-O-Hb, \u003c\/span\u003e\u003cspan\u003eS\u003c\/span\u003e\u003cspan\u003e-\u003c\/span\u003e\u003cspan\u003eH\u003c\/span\u003e\u003cspan\u003e-\u003c\/span\u003e\u003cspan\u003eO\u003c\/span\u003e\u003cspan\u003e,\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eH-S-OHb, H-O-O etc.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eWhy design SII\u0026amp;Hb band\u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003es pass\u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003einstead of \u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003eOIII\u0026amp;SII bands?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe filter is dedicated to capture H-beta and SII emission lines. We know that SII is s\u003c\/span\u003e\u003cspan\u003eingly ionized sulfur that emits light in the deep red part of the spectrum, beyond H-alpha, \u003c\/span\u003e\u003cspan\u003ebut the \u003c\/span\u003e\u003cspan\u003econtribution of H-beta to emission lines in nebulae \u003c\/span\u003e\u003cspan\u003eis frequently overlooked, even though it is t\u003c\/span\u003e\u003cspan\u003ehe second most common Hydrogen emission after the H-alpha line. \u003c\/span\u003e\u003cspan\u003eC\u003c\/span\u003e\u003cspan\u003eapturing more OIII will boost the existing signal but does not give more information. However Hb has \u003c\/span\u003e\u003cspan\u003ethe \u003c\/span\u003e\u003cspan\u003epotential to reveal structures not seen using OIII.\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eThe de\u003c\/span\u003e\u003cspan\u003esign\u003c\/span\u003e\u003cspan\u003e is to capture the H-beta emission line in the certain nebulas that contain some blue spectrum, this cannot be captured by \u003c\/span\u003e\u003cspan\u003eH-alpha, SII and OIII filters\u003c\/span\u003e\u003cspan\u003e. \u003c\/span\u003e\u003cspan\u003eGreater and richer details will be captured in many nebulae images to achieve results with a superior signal-to-noise ratio. \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIt is generally accepted that the OIII signal is a relatively weaker contributor to nebulae images. The OIII bandpass sensitivity is an important consideration for any nebulae filter.\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eMost colour cameras (OSC) use a RGGB Bayer pattern. The allocation of twice as many green pixels as compared to either red or blue pixels, enables a much-improved capture of the OIII signal.\u003c\/span\u003e\u003cspan\u003e Furthermore, \u003c\/span\u003e\u003cspan\u003ehigher OIII signal can be achieved by additional exposure using the Antlia ALP-T Ha\u0026amp;O3 filter, then isolating the GB channels, followed by synthesis of an OIII channel to add into your stack.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIn the situation where you may only want to add SII to your Ha\u0026amp;OIII data, then it may be preferable to buy one SII \u003c\/span\u003e\u003cspan\u003enarrowband\u003c\/span\u003e\u003cspan\u003e filter and \u003c\/span\u003e\u003cspan\u003eachieve a cleaner SII spectral emission. However, our new filter design (SII\u0026amp;Hb) includes the H-beta emission line which provides a distinct improvement in nebulae contrast and improved feature separation in Hb areas.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAntlia ALP-T Dual Band 5nm Ha\u0026amp;OIII filter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Dual band filter with a very narrow passband of 5nm in OIII and H-alpha to achieve a higher signal-to-noise ratio. The resulting contrast improvement for OSC is impressive.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAntlia ALP-T Dual Band 5nm SII\u0026amp;Hb filter: \u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003eDual band filter with a very narrow pass band of 5nm H-beta and S-II. This filter is ideal for \u003c\/span\u003e\u003cspan\u003ei\u003c\/span\u003e\u003cspan\u003encreas\u003c\/span\u003e\u003cspan\u003eing\u003c\/span\u003e\u003cspan\u003e contrast of nebulae that \u003c\/span\u003e\u003cspan\u003eemit\u003c\/span\u003e\u003cspan\u003e in the sulfur\u003c\/span\u003e\u003cspan\u003e and \u003c\/span\u003e\u003cspan\u003eH-beta\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003erange using OSC\u003c\/span\u003e\u003cspan\u003e.\u003c\/span\u003e\u003cspan\u003e It provides additional feature separation and isolation in Hb areas.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe advanced multi-coatings on Antlia ALP-T dual band filters effectively isolates the red, Ha line, blue-green, OIII line, deep red SII and the blue H-beta lines from emission nebulae, with almost total suppression of optical density (OD)4.5 on unwanted wavelengths from light pollution, moonlight, and airglow. The result is that both\u003c\/span\u003e\u003cspan\u003e the\u003c\/span\u003e\u003cspan\u003e ALP-T dual band 5nm Ha\u0026amp;OIII and SII\u0026amp;Hb filter create\u003c\/span\u003e\u003cspan\u003es\u003c\/span\u003e\u003cspan\u003e a superior signal-to-noise ratio and better contrast in your OSC images.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eThe main features and app\u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003eli\u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003ecation\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003ePasses SII 672.4nm line and H-Beta 486.1nm line\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eEngineered specifically for use with DSLR, CMOS, and CCD color cameras\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eUltra \u003c\/span\u003e\u003cspan\u003eFWHM \u003c\/span\u003e\u003cspan\u003e5nm \u003c\/span\u003e\u003cspan\u003ea\u003c\/span\u003e\u003cspan\u003ellows for increasing in exposure time\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eRecommended to be used with ALP-T Dual Band 5nm Ha\u0026amp;OIII filter to \u003c\/span\u003e\u003cspan\u003ecreate images with better \u003c\/span\u003e\u003cspan\u003esignal\u003c\/span\u003e\u003cspan\u003e to noise and better \u003c\/span\u003e\u003cspan\u003eisolation\u003c\/span\u003e\u003cspan\u003e between the 4 channels\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eSuppression of optical density (OD)4.5 on unwanted wavelengths improves signal-to-noise\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eExtremely steep bandpass and blackened edges \u003c\/span\u003e\u003cspan\u003eof unmounted sizes \u003c\/span\u003e\u003cspan\u003eto minimize internal reflections\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIdeal flat-top and moderate bandpass reducing spectrum down shifts\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIon Gun Assisted Deposition coating technology on the double-sided polished substrate making it the most consistent and accurate light pollution suppression filter\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eDesigned to suppress artificial lighting from Bortle scale 1 to Bortle scale 8\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIt can also be used as a narrowband filter for monochrome cameras to save imaging time\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eNear IR (NIR) is blocked up to 1100nm\u003c\/span\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e","brand":"Antlia","offers":[{"title":"2\" Mounted","offer_id":45077820997917,"sku":"ANT-ALP-T-SII-HB-2","price":497.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Antlia-ALP-T-Dualband-5nm-Filter.jpg?v=1685810699"},{"product_id":"antlia-alp-t-dualband-5nm-ha-oiii-highspeed-filter","title":"Antlia ALP-T Dualband 5nm Ha\/OIII Highspeed Filter","description":"\u003c!-- more --\u003e\n\u003cp\u003eALP-T Dual Band 5nm Highspeed Filters are further optimized to work with high-speed imaging systems by shifting slightly the passband and center wavelength. Using these highspeed filters between optics f\/2.2 and f\/3.6 shows much stronger and more contrasted in nebulae imaging compared to the standard version.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eFor optics f-ratios slower than f\/3.6, the standard ALP-T Dual Band 5nm filter is highly recommended. Meanwhile, if you seek the best possible performance with any optics faster than f\/2.2, the highspeed version is the best choice.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eBut keep in mind, the blue shift data by the computer simulation indicates narrowband filter shifts its bandwidth to shorter wavelengths with faster optics than f\/2, transmission at the emission wavelength may decrease perhaps 15%-20%. Although the Antlia ALP-T highspeed filter has similar transmission rates reduction in the H-a and OIII when the filter is used on fast optics, based on current standard version users’ data, it is evident that the filter still has the high performance of increase in emission nebula contrast and minimized halo.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eThe highspeed version price is the same as the standard filters and double benefits for the high-speed optics users. Worth mentioning is that Antlia inspected and measured products piece by piece with one of Agilent Cary’s professional spectrophotometer, resolution\/slit width is up to 0.2nm, which make us provide highly reliable and consistent products to you.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eThe Antlia ALP-T dual band 5nm series filter is a dual line-pass filter that was designed to be used primarily with one-shot color (OSC) cameras such as DSLR's and astronomical OSC cameras. It can also be used as a narrowband filter for monochrome cameras to save imaging time. The advanced multi-coatings on our ALP-T ultra dual band filter effectively isolate the red Ha and the blue-green OIII lines light from emission nebulae, with almost total suppression of optical density (OD)4.5 on unwanted wavelengths from light pollution, moonlight, and airglow. The result is that our ALP-T dual band 5nm filter creates a superior signal-to-noise ratio and better contrast in your images.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eThe filter enables the capture of the two main emission nebulae bands at the same time, whilst suppressing unwanted light pollution. It enables you to capture cleaner data and reduces the post-processing efforts to isolate faint details from the background light pollution.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eApplication and Performance: \u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eDesigned especially for fast astronomy optics, in particular f-ratios f\/2.2 to f\/3.6\u003c\/p\u003e\n\u003cp\u003eEngineered specifically for use with DSLR, CMOS, and CCD color cameras\u003c\/p\u003e\n\u003cp\u003eSuppression of optical density (OD)4.5 on unwanted wavelengths adds signal-to-noise\u003c\/p\u003e\n\u003cp\u003eExtremely steep bandpass edges minimize internal reflections\u003c\/p\u003e\n\u003cp\u003eIdeal flat-top and moderate bandpass reducing spectrum down shifts\u003c\/p\u003e\n\u003cp\u003eIon Gun Assisted Deposition coating technology on the double-sided polished substrate making it the most consistent and accurate light pollution suppression filter\u003c\/p\u003e\n\u003cp\u003eDesigned to suppress artificial lighting from Bortle scale 1 to Bortle scale 8\u003c\/p\u003e\n\u003cp\u003eNear IR (NIR) is blocked up to 1050nm\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTechnical Specifications:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ctable border=\"1\" align=\"LEFT\" width=\"585px\" bordercolor=\"#000000\" _innercreatetable=\"true\" units=\"hasPercent\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"22.6%\" bordercolor=\"#000000\"\u003e\u003cbr\u003e\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"25.3%\" bordercolor=\"#000000\"\u003e\u003cspan\u003eHydrogen-alpha\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"24.7%\" bordercolor=\"#000000\"\u003e\u003cspan\u003eOxygen III\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"22.6%\" bordercolor=\"#000000\"\u003e\u003cspan\u003eFWHM\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"25.3%\" bordercolor=\"#000000\"\u003e\u003cspan\u003e5nm\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"24.7%\" bordercolor=\"#000000\"\u003e\u003cspan\u003e5nm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"22.6%\" bordercolor=\"#000000\"\u003e\u003cspan\u003eCWL (Central Wavelength)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"25.3%\" bordercolor=\"#000000\"\u003e\u003cspan\u003e657.8nm\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"24.7%\" bordercolor=\"#000000\"\u003e\u003cspan\u003e502.2nm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"22.6%\" bordercolor=\"#000000\"\u003e\u003cspan\u003ePeak Transmission\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"25.3%\" bordercolor=\"#000000\"\u003e\u003cspan\u003e88%\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"24.7%\" bordercolor=\"#000000\"\u003e\u003cspan\u003e82%\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"22.6%\" bordercolor=\"#000000\"\u003e\u003cspan\u003eBlocking\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\" rowspan=\"1\" valign=\"top\" bordercolor=\"#000000\"\u003e\n\u003cspan\u003e≥\u003c\/span\u003e\u003cspan\u003eOD4.5 @ 300-1050nm\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"22.6%\" bordercolor=\"#000000\"\u003e\u003cspan\u003eFilter Thickness\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\" valign=\"top\" bordercolor=\"#000000\"\u003e\u003cspan\u003e2mm+\/-0.05mm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFilter Ring: \u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e2'' (M48*0.75)\u003c\/p\u003e\n\u003cp\u003eUltra-thin filter cell to minimize vignetting by maximize possible clear aperture\u003c\/p\u003e\n\u003cp\u003eBlack Anodized Finish\u003c\/p\u003e\n\u003cp\u003eLaser Engraving No Fading\u003c\/p\u003e","brand":"Antlia","offers":[{"title":"2\" Mounted","offer_id":45077823815965,"sku":"ANT-ALP-T-HS-2","price":540.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Antlia-ALP-T-Dualband-5nm-Filter_fd3f123c-ea97-42a5-8c88-c5ee1d114943.jpg?v=1685810834"},{"product_id":"antlia-alp-t-dualband-5nm-ha-oiii-filter","title":"Antlia ALP-T Dualband 5nm Ha\/OIII Filter","description":"\u003c!-- more --\u003e\n\u003cp\u003e\u003cspan\u003eThe \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eAntlia ALP-T \u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003edual band\u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003e 5nm\u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003eHa\u0026amp;OIII\u003c\/span\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cspan\u003e filter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e is a dual line-pass filter which was designed to be used primarily with one-shot color (OSC) cameras such as DSLR's \u003c\/span\u003e\u003cspan\u003eand\u003c\/span\u003e\u003cspan\u003e astronomical OSC cameras. It can also be used as a narrowband filter for monochrome cameras to save imaging time. The advanced multi-coatings on \u003c\/span\u003e\u003cspan\u003eAntlia\u003c\/span\u003e\u003cspan\u003e ALP-T ultra dual band filter effectively isolates the red \u003c\/span\u003e\u003cspan\u003eHa\u003c\/span\u003e\u003cspan\u003e and the blue-green OIII lines light from emission nebulae, with almost total suppression of \u003c\/span\u003e\u003cspan\u003eo\u003c\/span\u003e\u003cspan\u003eptical \u003c\/span\u003e\u003cspan\u003ed\u003c\/span\u003e\u003cspan\u003eensity \u003c\/span\u003e\u003cspan\u003e(\u003c\/span\u003e\u003cspan\u003eOD\u003c\/span\u003e\u003cspan\u003e)\u003c\/span\u003e\u003cspan\u003e4.5 on unwanted wavelengths from light pollution, moonlight, and airglow. The result is that our ALP-T dual\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eband 5nm filter creates a superior signal-to-noise ratio and better contrast in your images.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe filter enables the capture of the two main emission nebulae bands at the same time, whilst suppressing unwanted light pollution. It enables you to capture cleaner data and reduces the post processing efforts to isolate faint details from the background light pollution.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eApplication and Performance:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eEngineered specifically for use with DSLR, CMOS, and CCD color cameras\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eSuppression of \u003c\/span\u003e\u003cspan\u003eoptical density (OD)\u003c\/span\u003e\u003cspan\u003e4.5 on unwanted wavelengths adds signal-to-noise\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eExtremely steep \u003c\/span\u003e\u003cspan\u003ebandpass\u003c\/span\u003e\u003cspan\u003e edges minimize internal reflections\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIdeal flat-top and moderate bandpass reducing spectrum down shifts\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIon Gun Assisted Deposition coating technology on the double-sided polished substrate\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003emaking it the most\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003econsistent and accurate light pollution suppression filter \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eDesigned to suppress artificial lighting from \u003c\/span\u003e\u003cspan\u003eBortle scale\u003c\/span\u003e\u003cspan\u003e 1 to \u003c\/span\u003e\u003cspan\u003eBortle scale\u003c\/span\u003e\u003cspan\u003e 8\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eNear IR (NIR) is blocked up to 1100nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTechnical Specifications:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable cellspacing=\"0\" border=\"1\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"232\"\u003e\u003cbr\u003e\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"217\"\u003e\n\u003cp\u003e\u003cspan\u003eHydrogen-alpha\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"210\"\u003e\n\u003cp\u003e\u003cspan\u003eOxygen III\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"232\"\u003e\n\u003cp\u003e\u003cspan\u003eFWHM\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"217\"\u003e\n\u003cp\u003e\u003cspan\u003e5nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"210\"\u003e\n\u003cp\u003e\u003cspan\u003e5nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"232\"\u003e\n\u003cp\u003e\u003cspan\u003eCWL (Central Wavelength)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"217\"\u003e\n\u003cp\u003e\u003cspan\u003e656.3nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"210\"\u003e\n\u003cp\u003e\u003cspan\u003e500.7nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"232\"\u003e\n\u003cp\u003e\u003cspan\u003ePeak Transmission\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"217\"\u003e\n\u003cp\u003e\u003cspan\u003e9\u003c\/span\u003e\u003cspan\u003e2\u003c\/span\u003e\u003cspan\u003e%\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"top\" width=\"210\"\u003e\n\u003cp\u003e\u003cspan\u003e8\u003c\/span\u003e\u003cspan\u003e8\u003c\/span\u003e\u003cspan\u003e%\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"232\"\u003e\n\u003cp\u003e\u003cspan\u003eBlocking\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd colspan=\"2\" valign=\"top\" width=\"426\"\u003e\n\u003cp\u003e\u003cspan\u003e≥\u003c\/span\u003e\u003cspan\u003eOD4.5 @ 300-1100nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"top\" width=\"232\"\u003e\n\u003cp\u003e\u003cspan\u003eFilter Thickness\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd colspan=\"2\" valign=\"top\" width=\"426\"\u003e\n\u003cp\u003e\u003cspan\u003e2mm+\/-0.05mm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Antlia","offers":[{"title":"2\" Mounted","offer_id":45077868478749,"sku":"ANT-ALP-T-2","price":540.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Antlia-ALP-T-Dualband-5nm-Filter_422c581a-decd-4477-8e9a-260245f0f792.jpg?v=1685811364"},{"product_id":"antlia-quad-band-light-pollution-filter-2","title":"Antlia Quad Band Light Pollution Filter - 2\"","description":"\u003c!-- more --\u003e\n\u003cp data-mce-fragment=\"1\"\u003eThe Antlia Quad Band Anti-Light Pollution Filter is a light suppression filter for color and monochrome cameras. It is able to shoot most deep sky objects like galaxies, reflection nebulae, emission nebula, and star clusters from a Bortle 8 location to Bortle 1 as its spectral transmission passes through visible light region, near-ultraviolet (NUV) and near-infrared (NIR) region.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eAntlia Quad Band filter has a broad bandpass designed to cope with faster optics up to the f\/2 focal ratio.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eConsidering the high quantum efficiency (QE) characteristics of the latest cameras in the near-infrared region and this region is less susceptible to artificial light pollution, the Antlia Quad Band Light-Pollution Filter adds high transmission in the near-infrared (NIR) band. This spectrum design improves image signal-to-noise ratio and contrast by capturing signals in visible bands and NIR region, while also maintaining ood color balance and being easier to manage in post-processing. \u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eCertain full-spectrum objects like M51, M83 possess significant signal in the near-infrared (NIR) region, you can possibly capture these deep sky objects more contrasted with the Antlia Quad Band filter under light polluted condition.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eWhen using this filter with a camera that has UV\/IR cut protective glass, the visible band transmission signal is retained, but the IR cut limits your ability to capture targets with infrared signal.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eTherefore, the Antlia Quad Band filter is more suitable for cameras with AR protective glass as they can capture both NIR and visible band signals.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e\n\u003cp class=\"p\" data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eSpectrum\u003c\/span\u003e\u003c\/strong\u003e\u003cstrong data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e Specifications:\u003c\/span\u003e\u003c\/strong\u003e\u003cstrong data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" width=\"580\" data-mce-fragment=\"1\"\u003e\n\u003ctbody data-mce-fragment=\"1\"\u003e\n\u003ctr data-mce-fragment=\"1\"\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003c\/td\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eH-alpha\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"100\" valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e \u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eS-II\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"107\" valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e \u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eO-III\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"103\" valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e \u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eH-beta\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e \u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eNII\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-mce-fragment=\"1\"\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eWavelength\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e656.3nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"100\" valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e671.6nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e672.4nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"107\" valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e495.9nm,\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e500.7nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"103\" valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e486.1nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e658.3nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e654.8nm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-mce-fragment=\"1\"\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003ePeak Transmission\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e＞92%\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"100\" valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e＞92%\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"107\" valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e＞92%\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"103\" valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e＞92%\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e92%\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-mce-fragment=\"1\"\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eBlocking\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"534\" valign=\"center\" colspan=\"5\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e≥OD4@ 300-1\u003c\/span\u003e\u003cspan data-mce-fragment=\"1\"\u003e050\u003c\/span\u003e\u003cspan data-mce-fragment=\"1\"\u003enm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-mce-fragment=\"1\"\u003e\n\u003ctd valign=\"center\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eFilter Thickness\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd width=\"534\" valign=\"center\" colspan=\"5\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003e2mm+\/-0.05mm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe main features and application:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e- Anti-Light Pollution\u003c\/p\u003e\n\u003cp\u003eThe Antlia Quad Band filter is an effective solution for reducing light pollution, as it cuts out most of the orange-yellow lights from 589nm and part of blue lights from LEDs\u003c\/p\u003e\n\u003cp\u003e- Possible to shoot over 95% of deep sky objects\u003c\/p\u003e\n\u003cp\u003e- Unique spectral design offers more possibilities for astrophotography\u003c\/p\u003e\n\u003cp\u003e- High transmittance of the main emission lines Ha\/SII\/OIII\/H-Beta in the visible region, enhances the astrophotography's high SNR and contrast;\u003c\/p\u003e\n\u003cp\u003e- Near-infrared (NIR) region transmittance\u003c\/p\u003e\n\u003cp\u003e- Passing near infrared region is for shooting deep sky objects that cannot be shot with other filters without NIR transmission\u003c\/p\u003e\n\u003cp\u003e- The broad bandpass designed to cope with faster optics up to the f\/2 focal ratio.\u003c\/p\u003e\n\u003cp\u003e- Good color balance\u003c\/p\u003e\n\u003cp\u003e- It is easier to achieve color balance by adding the short-wavelength transmission\u003c\/p\u003e\n\u003cp\u003e- Superior optical reliability reduces post image processing\u003c\/p\u003e\n\u003cp\u003e- Basic Substrate: Optical, Single \/ Non-glued substrate\u003c\/p\u003e\n\u003cp\u003e- Surface Quality: S\/D (scratch\/dig)= 60\/40 (Refer to MIL-O-13830)\u003c\/p\u003e\n\u003cp\u003e- Transmitted Wavefront: Lambda\/4 or better.\u003c\/p\u003e\n\u003cp\u003e- Parallelism: less than 30 arcsec\u003c\/p\u003e\n\u003cp\u003e- Warranty: 3-years against delamination\u003c\/p\u003e","brand":"Antlia","offers":[{"title":"Default Title","offer_id":46978718892317,"sku":"ANT-QUAD-2","price":281.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Antlia-Quad-Band.jpg?v=1699120543"},{"product_id":"askar-6nm-color-magic-super-sii-oiii-d2-filter-2","title":"Askar 6nm Colour Magic Super SII\/OIII D2 Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual-band filter passing OIII (6.5nm) and SII (8.5nm) wavelengths\u003c\/li\u003e\n\u003cli\u003ePeak transmittance of 85% for maximum signal capture\u003c\/li\u003e\n\u003cli\u003eDesigned for color cameras to complete the \"Hubble Palette\" (SHO)\u003c\/li\u003e\n\u003cli\u003eStandard 2\" mounted format\u003c\/li\u003e\n\u003cli\u003e1.85mm thickness for near-parfocal performance with other filters\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 6nm Colour Magic Super SII\/OIII D2 Filter - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Askar 6nm Colour Magic Super D2 Filter isolates the Sulfur-II and Oxygen-III emission lines, capturing the two signals often missing from standard color camera workflows. With a narrow 8.5nm bandpass for SII (672nm) and a 6.5nm bandpass for OIII (500.7nm), this filter achieves a peak transmittance of 85% to preserve faint nebula detail. Its ≥OD5 blocking across the 200-1100nm spectrum ensures high-contrast images by eliminating light pollution and stellar bloat, making it the essential second filter for creating full Hubble Palette images with a one-shot-color camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e6.5nm\/8.5nm Bandpasses with 85% Peak Transmittance\u003c\/h3\u003e\n\u003cp\u003eThe filter's dual-passband design is precisely engineered to isolate key emission lines. The 6.5nm FWHM centered on the 500.7nm OIII line and the slightly wider 8.5nm FWHM on the 672nm SII line provide an excellent balance between signal strength and contrast. This design allows the filter to deliver over 85% of the light from these specific wavelengths while aggressively rejecting city glow and other unwanted background signal.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eUnlocking Full SHO Imaging for Your Color Camera\u003c\/h3\u003e\n\u003cp\u003eFor imagers using color cameras, duo-narrowband filters that pass H-alpha and OIII are common, but they leave out the critical Sulfur-II data needed for the classic Hubble Palette (SHO). The Askar Super D2 filter is the missing link, designed specifically to be used in conjunction with an Hα\/OIII filter. By capturing SII and additional OIII data in a separate session, you can gather all three channels required to assemble a full SHO image without the complexity of a monochrome camera and filter wheel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOptical Precision: OD5 Blocking and 30\" Parallelism\u003c\/h3\u003e\n\u003cp\u003eHigh-end imaging requires more than just narrow bandpasses. The Super D2 filter is built on a substrate with a parallelism of 30 arcseconds, preventing image degradation or focus shift when inserted into the optical train. With an optical density (OD) of 5 or greater, it blocks unwanted wavelengths from 200nm to 1100nm, effectively eliminating artifacts from UV, IR, and broadband light pollution for cleaner, higher-contrast results.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eAskar D2 Workflow: Adding the SII Channel to Your Data\u003c\/h3\u003e\n\u003cp\u003eIntegrating this filter into your imaging routine is straightforward. First, capture your primary data using a standard Hα\/OIII duo-band filter. Then, swap to the Askar Super D2 filter to capture the SII and OIII channels. In post-processing, you can combine the Hα from your first session with the SII from your second, and use the OIII data from whichever set is cleaner, giving you a complete H-S-O dataset. This two-filter approach is a powerful and cost-effective method for bringing monochrome-style palette flexibility to your color camera, and performs well even on fast optical systems.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I use the Askar 6nm D2 filter with my existing Hα\/OIII duo-band filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou use them in two separate imaging sessions. First, capture data with your Hα\/OIII filter. Then, without changing your framing, swap to the Askar D2 filter and capture more data for a similar total integration time. In processing, you will extract the Hα channel from the first session's data and the SII channel from the second session's data. You can then use the OIII data from either or both sessions to create a final SHO color image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the advantage of the Askar D2 filter's 6.5nm OIII and 8.5nm SII bandpasses?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e6.5nm OIII bandpass\u003c\/strong\u003e is very restrictive, which dramatically increases contrast and rejects moonlight or light pollution around the critical Oxygen-III lines. The slightly wider \u003cstrong\u003e8.5nm SII bandpass\u003c\/strong\u003e allows for a stronger signal from the typically fainter Sulfur-II line, helping to balance the data capture between the two wavelengths for better color results.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Askar 6nm D2 filter for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this filter is designed exclusively for astrophotography. Its bandpasses are extremely narrow (6.5nm and 8.5nm), and the human eye cannot gather enough light through such a restrictive filter to see anything. It requires long exposures with a camera to build up an image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Askar 6nm D2 filter work well with my f\/4 RASA or Hyperstar system?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. While not specifically designated as a \"high-speed\" filter, Askar has confirmed it performs well with fast optical systems. The filter's design minimizes the band-shifting effects that can occur with very fast focal ratios, ensuring you can still capture strong OIII and SII signals without significant transmission loss.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar D2 filter help me image targets like the Eagle Nebula (M16) in the Hubble Palette?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Eagle Nebula's \"Pillars of Creation\" are rich in all three narrowband gases. A standard duo-band filter captures the Hα and OIII, but misses the SII that traces the densest dust and ionization fronts. By using the Askar D2 filter, you capture that missing SII data, allowing you to assign Hα, SII, and OIII to the Red, Green, and Blue channels respectively in post-processing to create a vibrant, detailed SHO Hubble Palette image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the 1.85mm thickness of the Askar D2 filter make it parfocal with other brands?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e1.85 ± 0.05mm\u003c\/strong\u003e thickness is very close to the standard used by many filter manufacturers. This means it should be nearly parfocal, requiring minimal to no refocusing when swapping between filters of a similar thickness. This is a significant advantage when conducting the two-session imaging workflow required for SHO with a color camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eDual-Band Narrowband\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e2\" Mounted\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFWHM (OIII)\u003c\/td\u003e\n\u003ctd\u003e6.5nm ± 0.5nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFWHM (SII)\u003c\/td\u003e\n\u003ctd\u003e8.5nm ± 0.5nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCenter Wavelength (CWL)\u003c\/td\u003e\n\u003ctd\u003e500.7nm (OIII) \u0026amp; 672nm (SII)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003e≥85%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e≥OD5 @ 200-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e1.85mm ± 0.05mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Finish\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software \u0026amp; Drivers\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":47078711591197,"sku":"ASK-ASK2DNSOD2","price":447.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-Color-Magic-D2-Filter.jpg?v=1699985639"},{"product_id":"askar-colour-magic-sii-oiii-c2-filter-2","title":"Askar Colour Magic SII\/OIII C2 Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual-band filter passing SⅡ (672nm) and OIII (500.7nm) emission lines\u003c\/li\u003e\n\u003cli\u003eDesigned for one-shot-color cameras to capture data often missed by Hα\/OIII filters\u003c\/li\u003e\n\u003cli\u003e15nm±3nm bandpass for the Sulfur-II (SⅡ) line\u003c\/li\u003e\n\u003cli\u003e35nm±5nm bandpass for the Oxygen-III (OIII) line\u003c\/li\u003e\n\u003cli\u003e90% peak transmittance for high signal-to-noise ratio\u003c\/li\u003e\n\u003cli\u003eOD3 blocking from 200-1000nm suppresses light pollution and unwanted signal\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar Colour Magic SII\/OIII C2 Filter - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Askar Colour Magic C2 2\" filter isolates the Sulfur-II and Oxygen-III emission lines, capturing the \"missing\" SⅡ channel for one-shot-color camera users. With a tight 15nm±3nm bandpass at 672nm for SⅡ and a wider 35nm±5nm bandpass at 500.7nm for OIII, it achieves over 90% peak transmittance on these critical wavelengths. This design allows you to gather data for full SHO (Hubble Palette) style images without switching to a monochrome camera and filter wheel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe \"Missing Channel\" Solution: Adding SⅡ Data to Color Images\u003c\/h3\u003e\n\u003cp\u003eMost duo-band filters for color cameras focus on Hydrogen-alpha and Oxygen-III, leaving out the crucial Sulfur-II signal that reveals unique structures in many emission nebulae. The Askar Colour Magic C2 filter is engineered specifically to fill this gap. By capturing SⅡ and OIII simultaneously, it provides the data needed to complement your existing Hα\/OIII images, unlocking the ability to create full tricolor narrowband composites with a single color camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eAsymmetrical Design: 15nm SⅡ and 35nm OIII Bandpasses\u003c\/h3\u003e\n\u003cp\u003eThe filter features two different bandpasses to optimize signal capture for each emission line. The tighter 15nm±3nm FWHM for the SⅡ line provides excellent contrast and aggressively rejects light pollution for this often-fainter signal. The broader 35nm±5nm FWHM for OIII allows for greater light collection on this typically stronger signal, which is beneficial for reducing exposure times while still offering a significant improvement over broadband filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e90% Peak Transmittance for Maximum Contrast\u003c\/h3\u003e\n\u003cp\u003eAchieving over 90% peak transmittance at the 672nm and 500.7nm center wavelengths ensures that the maximum amount of valuable nebula light reaches your sensor. Combined with strong out-of-band blocking rated at OD3 from 200-1000nm, the C2 filter darkens the sky background significantly, even under moderately light-polluted skies. This high transmission and strong blocking work together to dramatically increase image contrast, making faint details in targets like the Trifid Nebula (M20) or the Eagle Nebula (M16) stand out clearly.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy use the Askar C2 SⅡ\/OIII filter instead of a standard Hα\/OIII filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Askar C2 is not a replacement for an Hα\/OIII filter; it's a \u003cstrong\u003ecomplement\u003c\/strong\u003e. Standard duo-band filters capture Hα and OIII. The C2 filter captures SⅡ and OIII, providing the third channel of data necessary for creating Hubble Palette (SHO) images with a color camera. You use both filters to acquire all three datasets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I combine data from the Askar C2 filter with my other images?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAfter capturing separate images with your Hα\/OIII filter and the Askar C2 SⅡ\/OIII filter, you would use image processing software like PixInsight or Photoshop. You can split the channels from each image to isolate the Hα, SⅡ, and OIII data, and then combine them into a single color image by assigning each signal to the Red, Green, and Blue channels as desired.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 35nm bandpass on the OIII channel of the Askar C2 filter wide enough for my light-polluted skies?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA 35nm bandpass provides a good balance between light pollution suppression and signal strength. While not as restrictive as a 3nm or 7nm filter, it is significantly better than a broadband filter and is effective in most suburban environments. The key benefit is shorter exposure times compared to ultra-narrowband filters, which can be an advantage for many imagers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat types of celestial objects benefit most from the Askar C2 SⅡ\/OIII filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eEmission nebulae with distinct regions of Sulfur-II emission are ideal targets. Objects like the \u003cstrong\u003eEagle Nebula (M16)\u003c\/strong\u003e, the \u003cstrong\u003eTrifid Nebula (M20)\u003c\/strong\u003e, and the \u003cstrong\u003eRosette Nebula (NGC 2237)\u003c\/strong\u003e show dramatic structural differences when SⅡ data is included, allowing for the creation of vibrant and detailed Hubble Palette images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Askar C2 SⅡ\/OIII filter with a monochrome camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile technically possible, it's not the intended use. With a monochrome camera, the sensor would capture both SⅡ and OIII light simultaneously, and you would not be able to separate them. For monochrome imaging, it is always better to use individual SⅡ and OIII single-bandpass filters to capture clean, isolated data for each channel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy are the bandpasses different for SⅡ (15nm) and OIII (35nm) on the Askar C2 filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis is a deliberate design choice to optimize performance. The \u003cstrong\u003eSⅡ signal is often weaker\u003c\/strong\u003e, so a tighter 15nm bandpass is used to increase contrast and reject more background light. The \u003cstrong\u003eOIII signal is typically stronger\u003c\/strong\u003e, so a wider 35nm bandpass allows more of this signal to be collected, reducing exposure times without sacrificing too much contrast.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eDual-Band Narrowband\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e2\" Mounted\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCenter Wavelength (CWL)\u003c\/td\u003e\n\u003ctd\u003e500.7nm (OIII) \u0026amp; 672nm (SⅡ)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFull Width Half-Max (FWHM)\u003c\/td\u003e\n\u003ctd\u003eOIII: 35nm ±5nm \/ SⅡ: 15nm ±3nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;90%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003eOD3 (0.1%) @ 200-1000nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGlass Thickness\u003c\/td\u003e\n\u003ctd\u003e2mm ± 0.05mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Finish\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar Colour Magic C2 SII\/OIII Filter - 2\"\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eProtective Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Drivers\/Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":47429342691613,"sku":"ASK-ASKAR2DBC2","price":167.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/image.png?v=1705009186"},{"product_id":"askar-colour-magic-sii-oiii-c1-filter-2","title":"Askar Colour Magic Ha\/OIII C1 Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual-bandpass filter for H-alpha (656.6nm) and Oxygen-III (500.7nm)\u003c\/li\u003e\n\u003cli\u003eAsymmetrical bandwidths: 15nm for H-alpha, 35nm for OIII\u003c\/li\u003e\n\u003cli\u003eGreater than 90% peak transmittance at primary emission lines\u003c\/li\u003e\n\u003cli\u003eOD3 (99.9%) blocking of light pollution from 200-1000nm\u003c\/li\u003e\n\u003cli\u003eStandard 2\" mounted format with 2mm thick substrate\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar Colour Magic Ha\/OIII C1 Filter - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Askar Colour Magic Ha\/OIII C1 filter isolates the two most important emission lines for nebula imaging, Hydrogen-alpha at 656.6nm and Oxygen-III at 500.7nm, with over 90% peak transmittance. Its design uses asymmetrical bandwidths—a tight 15nm±3nm for H-alpha and a wider 35nm±5nm for OIII—to capture strong signal from both wavelengths with a one-shot-color camera. By implementing OD3 blocking across the 200-1000nm spectrum, the C1 filter darkens the sky background for maximum image contrast, even from light-polluted locations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eIsolate Ha \u0026amp; OIII with 90% Peak Transmittance\u003c\/h3\u003e\n\u003cp\u003eThe Colour Magic C1 is engineered to pass only the light from ionized hydrogen (Hα at 656.6nm) and doubly ionized oxygen (OIII at 500.7nm). With a peak transmittance of over 90% at these critical wavelengths, your camera sensor collects maximum signal from emission nebulae like the North American Nebula (NGC 7000) or the Veil Nebula complex, while rejecting unwanted city lights and natural skyglow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eAsymmetrical Bandwidths: 15nm Ha and 35nm OIII for Color Balance\u003c\/h3\u003e\n\u003cp\u003eUnlike filters with identical bandwidths, the Askar C1 uses a purpose-built asymmetrical design. The H-alpha line is restricted to a tight 15nm±3nm bandpass for high-contrast detail in hydrogen-rich regions. The OIII bandpass is set to a much wider 35nm±5nm, allowing more signal to reach the sensor. This approach helps balance the often-weaker OIII signal against the typically dominant H-alpha, producing a richer, more natural color result directly from your one-shot-color (OSC) camera with less processing effort.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOD3 Blocking for High-Contrast Images in Light Pollution\u003c\/h3\u003e\n\u003cp\u003eEffective imaging requires not just passing the desired signal, but aggressively blocking everything else. The C1 filter provides OD3 blocking, equivalent to rejecting 99.9% of incoming light, across a vast 200-1000nm range outside of its passbands. This comprehensive blocking eliminates interference from common sources of light pollution like sodium and mercury-vapor streetlights, as well as moonlight and general skyglow, producing a dark, neutral background and making nebula structures stand out with dramatic contrast.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eAskar C1 vs. Symmetrical Filters: A Design for OSC Imaging\u003c\/h3\u003e\n\u003cp\u003eMany popular dual-band filters use very narrow, symmetrical bandpasses (e.g., 7nm for both Ha and OIII). While those filters offer slightly higher contrast and produce smaller stars, the Askar C1's asymmetrical design presents a distinct advantage for OSC imagers.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompetitor Advantage:\u003c\/strong\u003e Symmetrical ultra-narrowband filters provide the highest possible contrast on individual emission lines and are ideal for monochrome imaging or advanced processing techniques where data from each line is handled separately.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAskar C1 Advantage:\u003c\/strong\u003e By widening the OIII band to 35nm, the C1 captures more OIII signal relative to Ha in the same exposure time. This helps prevent the final color image from being overwhelmingly red and yields a more balanced initial result, reducing the need for complex color calibration in post-processing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy does the Askar Colour Magic C1 filter have different bandwidths for H-alpha and OIII?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe asymmetrical design is a deliberate choice to improve color balance for one-shot-color (OSC) cameras. The \u003cstrong\u003e15nm H-alpha band\u003c\/strong\u003e provides high contrast, while the wider \u003cstrong\u003e35nm OIII band\u003c\/strong\u003e allows more of the typically weaker OIII signal to be captured. This helps prevent images from being overwhelmingly red and produces a more natural color result with less processing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar C1 filter perform in Bortle 8\/9 skies?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Askar C1 filter is highly effective in heavily light-polluted skies. Its \u003cstrong\u003eOD3 blocking\u003c\/strong\u003e across the 200-1000nm spectrum aggressively rejects common sources of urban light pollution. By only passing the specific 656.6nm and 500.7nm wavelengths of nebulae, it dramatically darkens the sky background, allowing you to capture high-contrast images of emission nebulae even from the city.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Askar C1 filter for imaging the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this is not the right filter for broadband targets like galaxies or star clusters. The Askar C1 is a dual-bandpass filter that blocks almost all light except for specific emission lines. Since galaxies like M31 shine primarily in continuous-spectrum starlight, this filter would block the vast majority of their light, resulting in a very faint and incomplete image. A broadband light pollution filter is a better choice for galaxies from the city.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of color balance can I expect from the Askar C1 filter on the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOn a target like the Orion Nebula (M42), which is rich in both hydrogen and oxygen, the Askar C1 filter is designed to deliver a well-balanced color image with an OSC camera. The tight 15nm band will capture fine details in the red H-alpha regions, while the broad 35nm OIII band will ensure the blue-green structures in the Trapezium core are bright and prominent, avoiding an overly red final image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar C1 filter suitable for monochrome cameras?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile it can be used, it's not ideal. A monochrome camera cannot separate the H-alpha and OIII signals captured simultaneously by the Askar C1 filter. For monochrome imaging, it is far more effective to use separate, dedicated H-alpha and OIII single-bandpass filters to capture data for each channel individually, allowing for full processing control and palette creation (like the Hubble Palette).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the OD3 @ 200-1000nm rating on the Askar C1 filter mean?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eOD3\u003c\/strong\u003e stands for Optical Density 3, which means the filter blocks 99.9% of light outside its designated passbands. The \u003cstrong\u003e@ 200-1000nm\u003c\/strong\u003e specification indicates this high level of blocking is applied across the entire spectrum from deep ultraviolet to near-infrared. This ensures a very dark, high-contrast background free from light pollution and other unwanted signals.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eDual-Bandpass Narrowband\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWavelength 1 (CWL)\u003c\/td\u003e\n\u003ctd\u003e656.6nm (H-alpha)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWavelength 2 (CWL)\u003c\/td\u003e\n\u003ctd\u003e500.7nm (OIII)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandwidth (FWHM) H-alpha\u003c\/td\u003e\n\u003ctd\u003e15nm ± 3nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandwidth (FWHM) OIII\u003c\/td\u003e\n\u003ctd\u003e35nm ± 5nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003e\u0026gt; 90%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Efficiency\u003c\/td\u003e\n\u003ctd\u003eOD3 (99.9%)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e200nm - 1000nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e2mm ± 0.05mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Finish\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar Colour Magic Ha\/OIII C1 Filter - 2\"\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eProtective Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software \u0026amp; Drivers\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":47429347672349,"sku":"ASK-ASKAR2DBC1","price":167.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/image_8378cc30-ba51-4d4c-bfe1-c9fbd4710ebc.png?v=1705009394"},{"product_id":"askar-6nm-colour-magic-super-ha-oiii-d1-filter","title":"Askar 6nm Colour Magic Super Ha\/OIII D1 Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual-Bandpass: 8.5nm H-alpha \u0026amp; 6.5nm OIII\u003c\/li\u003e\n\u003cli\u003ePeak Transmittance: \u0026gt;85% at 500.7nm and 656.6nm\u003c\/li\u003e\n\u003cli\u003eLight Pollution Suppression: ≥OD5 blocking from 200-1100nm\u003c\/li\u003e\n\u003cli\u003eOptical Integrity: 30\" Parallelism\u003c\/li\u003e\n\u003cli\u003eThickness: 1.85mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 6nm Colour Magic Super Ha\/OIII D1 Filter - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Askar Colour Magic Super D1 duo-narrowband filter isolates the two most important emission lines for nebula photography, with a 6.5nm bandpass for Oxygen III and an 8.5nm bandpass for Hydrogen-alpha. It delivers over 85% peak transmittance at its central wavelengths of 500.7nm and 656.6nm, ensuring strong signal capture from emission targets. With aggressive out-of-band blocking rated at ≥OD5 from 200-1100nm and a substrate parallelism of 30 arcseconds, this filter dramatically increases contrast and maintains sharp star profiles even in heavily light-polluted skies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eCapturing Ha and OIII with 85% Transmittance\u003c\/h3\u003e\n\u003cp\u003eThis filter is engineered to capture H-alpha and OIII data simultaneously, making it an ideal tool for one-shot color cameras. The 8.5nm bandpass for H-alpha and 6.5nm for OIII are tight enough to reject urban skyglow but wide enough to collect significant signal. With a peak transmittance of 85%, you can acquire deep, high-contrast images of emission nebulae like the Veil Nebula (NGC 6960) or the Rosette Nebula (NGC 2237) without excessively long exposure times.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOD5 Blocking and 30\" Parallelism for Sharp Stars\u003c\/h3\u003e\n\u003cp\u003eThe optical quality of the Super D1 filter is defined by its rigorous specifications for blocking and physical precision. Its ≥OD5 blocking across the 200-1100nm spectrum effectively eliminates interference from sodium vapor lamps, LED streetlights, and natural skyglow, rendering the background sky nearly black. A 30\" parallelism tolerance ensures the filter surfaces are flat and parallel, preventing internal reflections and star distortions that can compromise the resolution of your main optics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eHigh Signal Capture Down to f\/1.9\u003c\/h3\u003e\n\u003cp\u003eWhile not designated specifically as a high-speed filter, the Askar Super D1 has been tested to perform exceptionally well with fast optical systems. Its design minimizes the band-shifting effects that can cause signal loss when narrowband filters are used with fast focal ratios. This makes it a reliable choice for modern astrographs, refractors, and even ultra-fast systems like a Celestron RASA or a telescope equipped with a Starizona HyperStar, maintaining high contrast and signal down to f\/1.9.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main purpose of the Askar D1 Duo-Narrowband filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Askar D1 filter is designed for astrophotographers using \u003cstrong\u003eone-shot color (OSC) cameras\u003c\/strong\u003e in light-polluted areas. It allows you to capture two key nebula emission lines, H-alpha and OIII, in a single exposure, which dramatically increases image contrast and reveals details that would otherwise be lost to skyglow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy are the H-alpha (8.5nm) and OIII (6.5nm) bandpasses on the Askar D1 different?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis is a deliberate design choice to balance signal strength with contrast. The tighter \u003cstrong\u003e6.5nm OIII bandpass\u003c\/strong\u003e provides excellent rejection of light pollution around that wavelength. The slightly wider \u003cstrong\u003e8.5nm H-alpha bandpass\u003c\/strong\u003e allows for slightly more signal collection, which can be beneficial for capturing fainter hydrogen structures in deep-sky objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Askar D1 filter perform on the Orion Nebula (M42) with an f\/6 refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt will perform exceptionally well. The Orion Nebula is extremely rich in both H-alpha and OIII emissions. The Askar D1 will isolate these signals, enhancing the red nebulosity and bringing out the blue-green structures in the core, all while suppressing skyglow. This allows for greater control over the bright Trapezium region while capturing the faint outer loops.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Askar D1 filter with a monochrome camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile you can, it's not the ideal application. A monochrome camera would capture both H-alpha and OIII signals on the same frame, preventing you from processing them separately. For monochrome imaging, using individual H-alpha and OIII filters provides far more flexibility and control over the final color image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar D1 suitable for my fast f\/2 RASA telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The filter's optical design has been tested to minimize band-shift and maintain high transmittance on systems as fast as \u003cstrong\u003ef\/1.9\u003c\/strong\u003e. This makes it a very capable choice for fast astrographs like the RASA, allowing you to take full advantage of the instrument's light-gathering power without significant signal degradation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar D1 filter control halos around bright stars?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eHalos are minimized through a combination of factors. The \u003cstrong\u003e≥OD5 blocking\u003c\/strong\u003e and anti-reflection coatings reduce stray light, while the \u003cstrong\u003e30\" parallelism\u003c\/strong\u003e specification ensures that light passes through without creating internal reflections that can cause halos and other artifacts around bright stars.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFWHM\u003c\/td\u003e\n\u003ctd\u003e8.5nm ± 0.5nm (H-alpha) \/ 6.5nm ± 0.5nm (OIII)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCenter Wavelength (CWL)\u003c\/td\u003e\n\u003ctd\u003e656.6nm (H-alpha) \u0026amp; 500.7nm (OIII)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003e85%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking\u003c\/td\u003e\n\u003ctd\u003e≥OD5 @ 200-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Thickness\u003c\/td\u003e\n\u003ctd\u003e1.85 ± 0.05mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Finish\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar 6nm Colour Magic Super Ha\/OIII D1 Filter - 2\"\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003ePlastic Protective Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Drivers \u0026amp; Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":49387561124125,"sku":"ASK-ASK2DNHOD1","price":447.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-Color-Magic-D2-Filter.jpg?v=1699985639"},{"product_id":"antlia-alp-t-dual-band-ha-oiii-3nm-filter","title":"Antlia ALP-T Dual Band Ha\u0026OIII 3nm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n    \u003cli\u003e\n        Precise Narrowband Filtering for Exceptional Contrast\n    \u003c\/li\u003e\n    \u003cli\u003e\n        Enhanced Transmission for Superior Signal-to-Noise Ratio\n    \u003c\/li\u003e\n    \u003cli\u003e\n        Anti-Reflection Coating to Reduce Halo Effect\n    \u003c\/li\u003e\n    \u003cli\u003e\n        Optimized for Fast Optics up to f\/2\n    \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n    \u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n    \u003cli\u003eSpecifications\u003c\/li\u003e\n    \u003cli\u003eIn the Box\u003c\/li\u003e\n    \u003c!--\u003cli\u003eDownloads\u003c\/li\u003e--\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n    \u003cli class=\"active\"\u003e       \n        \u003cdiv\u003e\n            \u003c!-- Title image text --\u003e\n            \u003cdiv class=\"DAV-bg-light\"\u003e\n                \u003c!-- Main Image --\u003e\n                \u003cdiv class=\"DAV-section-center\"\u003e\n                    \u003ch2\u003eAntlia ALP-T Dual Band Ha\u0026amp;OIII 3nm - Overview\u003c\/h2\u003e\n        \n                    \u003cp\u003e\n                        The Antlia ALP-T Dual Band Filter Set is a high-performance toolset designed for astrophotographers who demand precision, contrast, and exceptional image quality. This set includes the Ha\u0026amp;OIII 3nm Filter and the SII\u0026amp;Hβ 3.5nm Filter, providing unmatched narrowband imaging capability for capturing deep-sky objects with remarkable clarity and detail.                    \n                    \u003c\/p\u003e\n                \u003c\/div\u003e\n            \u003c\/div\u003e\n\n            \u003c!-- Features Grid --\u003e\n            \u003cdiv class=\"DAV-feature-grid\"\u003e\n                \u003c!-- Feature Box 1 --\u003e\n                \u003cdiv class=\"DAV-feature-box\"\u003e\n                    \u003c!--\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623174875.jpg?v=1733252057\" alt=\"Feature 3\" class=\"DAV-feature-img\"\u003e--\u003e\n                    \u003ch3\u003eHigh Signal-to-Noise Ratio\u003c\/h3\u003e\n                    \u003cp\u003e\n                        Superior imaging in challenging light conditions.\n                    \u003c\/p\u003e\n                \u003c\/div\u003e\n                \u003c!-- Feature Box 2 --\u003e\n                \u003cdiv class=\"DAV-feature-box\"\u003e\n                    \u003c!--\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623174875.jpg?v=1733252057\" alt=\"Feature 3\" class=\"DAV-feature-img\"\u003e--\u003e\n                    \u003ch3\u003eVersatile Applications\u003c\/h3\u003e\n                    \u003cp\u003e\n                        Suitable for capturing traditional RGB images or creating artistic false-color palettes.\n                    \u003c\/p\u003e\n                \u003c\/div\u003e\n                \u003c!-- Feature Box 3 --\u003e\n                \u003cdiv class=\"DAV-feature-box\"\u003e\n                    \u003c!--\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623174875.jpg?v=1733252057\" alt=\"Feature 3\" class=\"DAV-feature-img\"\u003e--\u003e\n                    \u003ch3\u003eEasy Integration\u003c\/h3\u003e\n                    \u003cp\u003e\n                        Compatible with optics slower than f\/4, with high-speed versions available for faster setups.\n                    \u003c\/p\u003e\n                \u003c\/div\u003e\n            \u003c\/div\u003e\n\n            \u003c!--\n            \u003cdiv class=\"DAV-bg-light DAV-section-center\"\u003e\n                \u003ch3\u003eWhy Choose the Antlia ALP-T Filter Set?\u003c\/h3\u003e\n                \u003cp\u003eCombining these filters allows astrophotographers to capture the four key emission lines (H-alpha, OIII, SII, Hβ) in unparalleled detail. The advanced multi-coating technology suppresses light pollution, moonlight, and airglow while delivering outstanding contrast and clarity. Whether you’re imaging from urban or rural locations, this filter set ensures breathtaking astrophotography results.\u003c\/p\u003e\n                \u003cdiv class=\"DAV-grid-img\"\u003e\n                    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\" alt=\"Highlight 1\"\u003e\n                    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\" alt=\"Highlight 2\"\u003e\n                \u003c\/div\u003e\n            \u003c\/div\u003e\n            --\u003e\n            \n            \u003c!-- image text --\u003e\n            \u003cdiv class=\"DAV-section-container\"\u003e\n                \u003c!-- Image Section --\u003e\n                \u003cdiv class=\"DAV-section-img\"\u003e\n                    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\" alt=\"Ha\u0026amp;Oiii\"\u003e\n                \u003c\/div\u003e\n\n                \u003c!-- Text Section --\u003e\n                \u003cdiv class=\"DAV-section-text\"\u003e\n                    \u003ch3\u003eHa\u0026amp;OIII 3nm Filter\u003c\/h3\u003e                \n                    \u003cp\u003e\n                        This dual narrowband filter isolates the H-alpha (656.3nm) and OIII (500.7nm) emission lines, optimized for use with color cameras. With a Full Width Half Maximum (FWHM) bandwidth of 3nm, it effectively blocks unwanted wavelengths, including light pollution, moonlight, and airglow. The result is an enhanced signal-to-noise ratio and strikingly detailed nebula images.\n                    \u003c\/p\u003e\n                    \u003cul\u003e\n                        \u003cli\u003e\n\u003cb\u003ePrecise Transmission:\u003c\/b\u003e Passes H-alpha and OIII lines exclusively for improved contrast in celestial images.\u003c\/li\u003e\n                        \u003cli\u003e\n\u003cb\u003eExceptional Filtering:\u003c\/b\u003e Blocks optical density (OD) 4.5 on stray wavelengths, suppressing light pollution and enhancing nebula visibility.\u003c\/li\u003e\n                        \u003cli\u003e\n\u003cb\u003eIdeal for OSC Cameras:\u003c\/b\u003e Designed for color cameras, with applications in luminance filtering for monochrome cameras.\u003c\/li\u003e\n                        \u003cli\u003e\n\u003cb\u003eFlat-Top Bandpass:\u003c\/b\u003e Reduces spectrum shifts for consistent imaging performance, even under varying conditions.\u003c\/li\u003e\n                    \u003c\/ul\u003e\n                \u003c\/div\u003e\n            \u003c\/div\u003e\n\n            \u003c!--\n            \u003cdiv class=\"DAV-section-container\"\u003e\n                \u003cdiv class=\"DAV-section-text\"\u003e\n                    \u003ch3\u003eSII\u0026Hβ 3.5nm Filter\u003c\/h3\u003e                \n                    \u003cp\u003e\n                        The SII\u0026Hβ filter captures the deep red Sulfur-II (672.4nm) and blue Hydrogen-Beta (486.1nm) emission lines, providing complementary spectral data to the Ha\u0026OIII filter. It’s perfect for creating detailed narrowband images and vibrant false-color palettes.\n                    \u003c\/p\u003e\n                    \u003cul\u003e\n                        \u003cli\u003e\u003cb\u003eDual Narrowband Capture:\u003c\/b\u003e Captures SII and H-beta lines simultaneously for rich spectral imaging.\u003c\/li\u003e\n                        \u003cli\u003e\u003cb\u003eEnhanced Imaging Contrast:\u003c\/b\u003e Blocks optical density (OD) 4.5 on unwanted wavelengths, optimizing contrast even in light-polluted conditions.\u003c\/li\u003e\n                        \u003cli\u003e\u003cb\u003eCreative Color Palettes:\u003c\/b\u003e Enables various combinations like H-O-Hβ or S-H-O for unique astrophotography.\u003c\/li\u003e\n                    \u003c\/ul\u003e        \n                \u003c\/div\u003e\n                \u003cdiv class=\"DAV-section-img\"\u003e\n                    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\" alt=\"Sii\u0026Hb\"\u003e\n                \u003c\/div\u003e\n            \u003c\/div\u003e\n            --\u003e\n\n        \u003c\/div\u003e\n    \u003c\/li\u003e\n\n    \u003cli\u003e\n        \u003ch2\u003eHa\u0026amp;OIII 3nm Filter\u003c\/h2\u003e\n        \u003ctable class=\"DAV-specifications\"\u003e\n            \u003ctbody\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eFWHM\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003e3nm\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003ePeak Transmission\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003e90% (H-alpha), 82% (OIII)\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eBlocking\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003e≥ OD4.5 (300-1100nm)\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eFilter Thickness\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003e2mm\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eRing Design\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eUltra-thin filter cell with M48*0.75 thread to reduce vignetting\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003c!-- Add more rows as needed --\u003e\n            \u003c\/tbody\u003e\n        \u003c\/table\u003e\n        \u003c!--\n        \u003ch2\u003eSII\u0026Hβ 3.5nm Filter\u003c\/h2\u003e\n        \u003ctable class=\"DAV-specifications\"\u003e\n            \u003ctbody\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eFWHM\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003e3.5mm\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003ePeak Transmission\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003e90% (SII), 85% (Hβ)\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eBlocking\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003e≥ OD4.5 (300-1100nm)\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n                \u003ctr\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eRing Design\u003c\/p\u003e\n                    \u003c\/td\u003e\n                    \u003ctd\u003e\n                        \u003cp\u003eUltra-thin and black anodized to minimize reflections\u003c\/p\u003e\n                    \u003c\/td\u003e\n                \u003c\/tr\u003e\n            \u003c\/tbody\u003e\n        \u003c\/table\u003e\n        --\u003e\n    \u003c\/li\u003e\n    \n    \u003cli\u003e\n        \u003cul class=\"DAV-grid\"\u003e\n            \u003cli class=\"DAV-grid-item\"\u003e\n                \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\" alt=\"HaOIII\" class=\"DAV-img-box\"\u003e\n                \u003cdiv\u003e\n                    \u003cp class=\"DAV-item-title\"\u003eHa\u0026amp;OIII Filter\u003c\/p\u003e\n                    \u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n                \u003c\/div\u003e\n            \u003c\/li\u003e\n            \u003c!--\n            \u003cli class=\"DAV-grid-item\"\u003e\n                \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\" alt=\"SiiHb\" class=\"DAV-img-box\"\u003e\n                \u003cdiv\u003e\n                    \u003cp class=\"DAV-item-title\"\u003eSii\u0026Hb Filter\u003c\/p\u003e\n                    \u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n                \u003c\/div\u003e\n            \u003c\/li\u003e\n            --\u003e\n        \u003c\/ul\u003e          \n    \u003c\/li\u003e\n    \u003c!--\n    \u003cli\u003e\n        \u003cul class=\"DAV-grid\"\u003e\n            \u003cli class=\"DAV-grid-item\"\u003e\n                \u003ca href=\"\" target=\"_blank\"\u003e\n                    \u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 512 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\"\/\u003e\u003c\/svg\u003e\n                    \u003cdiv\u003e\n                    \u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n                \u003c\/div\u003e\n                \u003c\/a\u003e\n            \u003c\/li\u003e\n            \u003cli class=\"DAV-grid-item\"\u003e\n                \u003ca href=\"\" target=\"_blank\"\u003e\n                    \u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\/\u003e\u003c\/svg\u003e                \u003cdiv\u003e\n                    \u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n                \u003c\/div\u003e\n                \u003c\/a\u003e\n            \u003c\/li\u003e\n        \u003c\/ul\u003e\n    \u003c\/li\u003e\n    --\u003e\n\u003c\/ul\u003e\n","brand":"Antlia","offers":[{"title":"Default Title","offer_id":49428837531933,"sku":"ANT-ALP-T-3NM-HAOIII","price":554.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_0b67e995-1011-4adb-9f12-948552797683.webp?v=1733252577"},{"product_id":"antlia-alp-t-dual-band-sii-hb-3-5nm","title":"Antlia ALP-T Dual Band SII\u0026Hβ 3.5nm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003ePrecise Narrowband Filtering for Exceptional Contrast\u003c\/li\u003e\n\u003cli\u003eEnhanced Transmission for Superior Signal-to-Noise Ratio\u003c\/li\u003e\n\u003cli\u003eAnti-Reflection Coating to Reduce Halo Effect\u003c\/li\u003e\n\u003cli\u003eOptimized for Fast Optics up to f\/2\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003c!-- Title image text --\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003c!-- Main Image --\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAntlia ALP-T Dual Band SII\u0026amp;Hβ 3.5nm - Overview\u003c\/h2\u003e\n\u003cp\u003eThe Antlia ALP-T Dual Band Filter Set is a high-performance toolset designed for astrophotographers who demand precision, contrast, and exceptional image quality. This set includes the Ha\u0026amp;OIII 3nm Filter and the SII\u0026amp;Hβ 3.5nm Filter, providing unmatched narrowband imaging capability for capturing deep-sky objects with remarkable clarity and detail.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- Features Grid --\u003e\n\u003cdiv class=\"DAV-feature-grid\"\u003e\n\u003c!-- Feature Box 1 --\u003e\n\u003cdiv class=\"DAV-feature-box\"\u003e\n\u003ch3\u003eHigh Signal-to-Noise Ratio\u003c\/h3\u003e\n\u003cp\u003eSuperior imaging in challenging light conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!-- Feature Box 2 --\u003e\n\u003cdiv class=\"DAV-feature-box\"\u003e\n\u003ch3\u003eVersatile Applications\u003c\/h3\u003e\n\u003cp\u003eSuitable for capturing traditional RGB images or creating artistic false-color palettes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!-- Feature Box 3 --\u003e\n\u003cdiv class=\"DAV-feature-box\"\u003e\n\u003ch3\u003eEasy Integration\u003c\/h3\u003e\n\u003cp\u003eCompatible with optics slower than f\/4, with high-speed versions available for faster setups.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-section-container\"\u003e\n\u003cdiv class=\"DAV-section-text\"\u003e\n\u003ch3\u003eSII\u0026amp;Hβ 3.5nm Filter\u003c\/h3\u003e\n\u003cp\u003eThe SII\u0026amp;Hβ filter captures the deep red Sulfur-II (672.4nm) and blue Hydrogen-Beta (486.1nm) emission lines, providing complementary spectral data to the Ha\u0026amp;OIII filter. It’s perfect for creating detailed narrowband images and vibrant false-color palettes.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eDual Narrowband Capture:\u003c\/b\u003e Captures SII and H-beta lines simultaneously for rich spectral imaging.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eEnhanced Imaging Contrast:\u003c\/b\u003e Blocks optical density (OD) 4.5 on unwanted wavelengths, optimizing contrast even in light-polluted conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eCreative Color Palettes:\u003c\/b\u003e Enables various combinations like H-O-Hβ or S-H-O for unique astrophotography.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-section-img\"\u003e\u003cimg alt=\"Sii\u0026amp;Hb\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\" data-mce-src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\"\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ch2\u003eSII\u0026amp;Hβ 3.5nm Filter\u003c\/h2\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003eFWHM\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003e3.5mm\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003ePeak Transmission\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003e90% (SII), 85% (Hβ)\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003eBlocking\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003e≥ OD4.5 (300-1100nm)\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003eRing Design\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003eUltra-thin and black anodized to minimize reflections\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cimg class=\"DAV-img-box\" alt=\"HaOIII\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\" data-mce-src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_67b5496f-f728-4fd1-b82a-563e5e8c9962.webp?v=1733252057\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eSII\u0026amp;Hβ Filter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Antlia","offers":[{"title":"Default Title","offer_id":49428843594013,"sku":"ANT-ALP-T-3NM-SIIHB","price":511.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-filter-3nm-ha-oiii-antlia-alp-t-dual-band-highspeed-3nm-ha-oiii-3-5nm-sii-hb-2-mounted-filters-42550623338715_1024x_0b67e995-1011-4adb-9f12-948552797683.webp?v=1733252577"},{"product_id":"optolong-l-para-ha-oiii-10nm-filter-2","title":"Optolong L-Para HA\/OIII 10nm Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual Narrowband H-Alpha \u0026amp; OIII Filter\u003c\/li\u003e\n\u003cli\u003eSuppresses Mercury, Sodium \u0026amp; LED Light Pollution\u003c\/li\u003e\n\u003cli\u003eOptimized for Fast-Ratio Systems (RASA, HyperStar)\u003c\/li\u003e\n\u003cli\u003eAdvanced Anti-Halo Optical Design\u003c\/li\u003e\n\u003cli\u003eDurable Ion-Assisted Deposition Coatings\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eOptolong L-Para HA\/OIII 10nm Filter - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Optolong L-Para HA\/OIII filter is a dual narrowband filter designed to isolate critical nebula emission lines from hydrogen-alpha and oxygen-III. It aggressively suppresses common sources of urban light pollution, including mercury-vapor, sodium, and LED streetlights. This targeted filtration darkens the sky background, significantly increasing the contrast of emission nebulae for more detailed and vibrant astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDual-Bandpass Design for High-Contrast Nebula Imaging\u003c\/h3\u003e\n\u003cp\u003eThe L-Para filter targets the two most prominent emission lines in most nebulae—Hydrogen-alpha and Oxygen-III. By selectively passing light from these wavelengths while rejecting the rest of the spectrum, it renders the sky background exceptionally dark. This approach dramatically enhances the contrast between your deep-sky target and the surrounding sky, revealing faint structures that would otherwise be lost to light pollution.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eUniversal Compatibility: Engineered for Fast and Standard Telescopes\u003c\/h3\u003e\n\u003cp\u003eA key design goal for the L-Para was compatibility across a wide range of instruments. It is engineered to maintain high transmission rates and color fidelity not only in standard focal ratio telescopes but also in very fast optical systems like RASA or HyperStar setups. The filter's performance holds up even when receiving steep, oblique light rays, ensuring one filter can serve your entire collection of telescopes without compromise.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eAdvanced Halo Suppression for Cleaner Stars\u003c\/h3\u003e\n\u003cp\u003eHalos around bright stars can obscure faint, nearby nebulosity and detract from the final image. The Optolong L-Para features an optimized coating stack specifically designed to minimize these artifacts. This meticulous anti-halo engineering results in cleaner, more precise star images and ensures that the delicate details of your target nebula remain the central focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDurable Ion-Assisted Coatings for Lasting Reliability\u003c\/h3\u003e\n\u003cp\u003eOptolong utilizes an ion-assisted deposition coating process to produce the L-Para filter. This advanced technique creates a hard, dense coating that is highly resistant to scratching and environmental degradation. The result is a filter with stable, consistent wavelength transmission that will not deviate with temperature changes, providing reliable imaging results for years to come.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of objects is the Optolong L-Para filter best for?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Optolong L-Para is specifically designed for imaging \u003cstrong\u003eemission nebulae\u003c\/strong\u003e, which are rich in Hydrogen-alpha and Oxygen-III light. It excels on targets like the Orion Nebula (M42), the Lagoon Nebula (M8), and the North American Nebula (NGC 7000).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Optolong L-Para improve images from light-polluted skies?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt uses a dual narrowband design that selectively passes light from \u003cstrong\u003eHa and OIII\u003c\/strong\u003e while blocking broad-spectrum light from artificial sources like mercury, sodium, and LED streetlights. This darkens the sky background and dramatically boosts the contrast of your target.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Optolong L-Para work with my fast f\/2 RASA telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the L-Para is engineered for compatibility with a wide range of optical systems, including very fast focal ratios like those found on \u003cstrong\u003eRASA and HyperStar systems\u003c\/strong\u003e. It's designed to maintain high transmission and avoid band-shifting even with the steep light cones from these instruments.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong L-Para for imaging galaxies like Andromeda (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile you can, it's not ideal. The L-Para is a narrowband filter that blocks most of the light from \u003cstrong\u003ebroadband targets like galaxies\u003c\/strong\u003e, which emit light across the entire visible spectrum. For galaxies, a broadband light pollution filter or unfiltered imaging from a dark site is recommended.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat makes the Optolong L-Para's halo control notable?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOptolong has specifically optimized the L-Para's coating design to \u003cstrong\u003esuppress halos\u003c\/strong\u003e, which are the rings of light that can appear around very bright stars. This results in cleaner star fields and prevents nebulosity near bright stars from being obscured.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong L-Para a good choice for a one-shot-color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. Dual narrowband filters like the L-Para are an excellent match for \u003cstrong\u003eone-shot-color (OSC) cameras\u003c\/strong\u003e. They allow you to capture both Ha and OIII data simultaneously, simplifying your workflow and producing dramatic, high-contrast nebula images even from urban locations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/optolong-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eOptolong 3-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Optolong","offers":[{"title":"Default Title","offer_id":50077460758813,"sku":"OPT-AS100221","price":362.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-L-Para-Filter.png?v=1750275530"},{"product_id":"idas-nbz-ii-ha-oiii-nebula-booster-filter","title":"IDAS NBZ-II HA OIII Nebula Booster Filter","description":"\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e2\"\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eOIII 8nm (+\/-0.4nm)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eH-alpha 9.5nm (+\/- 0.4nm) (originally designed at 10nm, but on a measured basis, it's 9.5nm.)\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"IDAS","offers":[{"title":"Default Title","offer_id":50122991141149,"sku":"IDA-NBZ-II-48ST2","price":418.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/IDASNBZ-II48mmST2MBTIAD720x600..png?v=1751480220"},{"product_id":"optolong-l-quad-enhance-filter","title":"Optolong L-Quad Enhance Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eQuad-bandpass design for color cameras\u003c\/li\u003e\n\u003cli\u003eSuppresses light pollution with OD2-OD4 blocking depth\u003c\/li\u003e\n\u003cli\u003eMaintains sharpness with a λ\/4 transmitted wavefront\u003c\/li\u003e\n\u003cli\u003eConstructed from 1.85mm thick optical glass\u003c\/li\u003e\n\u003cli\u003eEnsures no double images with 30s parallelism\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eOptolong L-Quad Enhance Filter\u003c\/h2\u003e\n\u003cp\u003eThe Optolong L-Quad Enhance Filter is a specialized quad-bandpass light pollution filter for one-shot-color cameras, built on a 1.85mm optical glass substrate. It delivers deep suppression of artificial and natural skyglow with an optical density of OD2-OD4 across a broad 300-1000nm blocking range, isolating key celestial emission lines while preserving broadband color. With a transmitted wavefront held to λ\/4 and parallelism of 30 arcseconds, the L-QEF maintains sharp, detailed star images across the entire field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eQuad-Bandpass Light Pollution Suppression at OD2-OD4\u003c\/h3\u003e\n\u003cp\u003eDesigned specifically for color cameras, the L-Quad Enhance Filter utilizes four precisely defined bandpasses to combat light pollution. With a blocking depth of OD2 to OD4, it eliminates between 99% and 99.99% of unwanted wavelengths from sources like mercury and sodium streetlights, dramatically increasing the contrast between your target and the sky background. This aggressive suppression allows you to capture clean data even from suburban locations or under moonlight.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eλ\/4 Wavefront for Broadband Targets like Galaxies \u0026amp; Clusters\u003c\/h3\u003e\n\u003cp\u003eUnlike narrowband filters that isolate only emission lines, the L-QEF is engineered to capture both nebulae and broadband targets. Its passbands are chosen to preserve the continuous spectrum of galaxies and the subtle star colors in clusters, providing a more natural color balance directly out of the camera. The guaranteed λ\/4 transmitted wavefront ensures that the filter does not introduce optical errors, preserving the sharpness required to resolve fine details in targets like the Sculptor Galaxy (NGC 253) or the stars of the Double Cluster (NGC 869\/884).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e30s Parallelism for Pinpoint Stars Across the Field\u003c\/h3\u003e\n\u003cp\u003eOptical precision is critical in any filter, and the L-QEF is held to strict mechanical tolerances. A parallelism of 30 arcseconds guarantees that the two faces of the filter are almost perfectly parallel. This prevents the introduction of image shift or distorted stars, ensuring that pinpoint stellar images from your telescope's optics remain perfectly round and sharp from edge to edge.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDurable Ion-Assisted Coatings on 1.85mm Substrate\u003c\/h3\u003e\n\u003cp\u003eThe L-Quad Enhance Filter's multi-layer coatings are applied using an advanced ion-assisted deposition process. This technology creates a dense, durable, and scratch-resistant surface that is easy to clean and maintains its spectral performance over time. Built on a 1.85mm thick optical glass substrate with a 60\/40 surface quality, the filter is parfocal with other standard astronomy filters, minimizing the need to refocus when using a filter wheel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Optolong L-Quad Enhance Filter differ from a dual-band nebula filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA dual-band filter typically isolates only the H-alpha and OIII emission lines, which is ideal for emission nebulae but can result in unnatural colors for broadband targets like galaxies and star clusters. The \u003cstrong\u003eOptolong L-Quad Enhance Filter\u003c\/strong\u003e uses four passbands, which allows it to capture a more complete spectrum, resulting in better color balance for all types of deep-sky objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong L-Quad Enhance Filter to image the Sculptor Galaxy (NGC 253) from a suburban backyard?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, this is an excellent use case for the \u003cstrong\u003eL-QEF\u003c\/strong\u003e. The filter is specifically designed to suppress common forms of light pollution while preserving the continuous spectrum of galaxies. It will help darken the sky background and increase the contrast of NGC 253's dust lanes and star-forming regions, making it possible to capture a high-quality image from light-polluted areas.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Optolong L-QEF perform on the North American Nebula (NGC 7000) with a one-shot-color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eL-QEF\u003c\/strong\u003e will perform very well. For large emission nebulae like the North American Nebula, the filter will isolate the critical red (H-alpha) and blue-green (H-beta\/OIII) wavelengths while blocking skyglow. This dramatically boosts the nebula's contrast against the background, revealing faint structures and details that would otherwise be lost.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the L-Quad Enhance Filter produce halos around bright stars?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eOptolong L-Quad Enhance Filter\u003c\/strong\u003e is designed with advanced anti-reflection coatings to minimize halos and other internal reflections around bright stars. User tests confirm that it controls halos effectively, producing clean stellar profiles even on challenging targets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the λ\/4 wavefront specification mean for my images with the L-QEF?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA \u003cstrong\u003eλ\/4 (1\/4 wave) transmitted wavefront\u003c\/strong\u003e is a measure of optical flatness and precision. It guarantees that the filter will not degrade the quality of the light passing through it, preserving the sharpness and resolution delivered by your telescope. This is crucial for capturing fine details and maintaining tight, point-like stars.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong L-Quad Enhance Filter suitable for imaging under a full moon?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, while no filter can eliminate all moonlight, the \u003cstrong\u003eL-Quad Enhance Filter's\u003c\/strong\u003e strong suppression of background skyglow makes it highly effective at mitigating the impact of the Moon. It allows you to continue imaging on nights that would otherwise be unusable, significantly increasing your opportunities to capture data.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate\u003c\/td\u003e\n\u003ctd\u003eOptical glass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThickness\u003c\/td\u003e\n\u003ctd\u003e1.85mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e300-1000nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Depth\u003c\/td\u003e\n\u003ctd\u003eOD2-OD4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmitted Wavefront RMS\u003c\/td\u003e\n\u003ctd\u003eλ\/4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/optolong-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eOptolong 3-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Optolong","offers":[{"title":"2\" Mounted","offer_id":50289892688157,"sku":"OPT-14702","price":278.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-L-Quad-Enhance-Filter.jpg?v=1756170392"},{"product_id":"askar-3nm-colour-magic-ultra-ha-oiii-e1-filter-2","title":"Askar 3nm Colour Magic Ultra Ha\/OIII E1 Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual-bandpass for Hydrogen-alpha (656.6nm) and Oxygen-III (500.7nm)\u003c\/li\u003e\n\u003cli\u003eUltra-narrow 3.7nm (Ha) and 4.0nm (OIII) FWHM bandwidths\u003c\/li\u003e\n\u003cli\u003e85% peak transmittance at both center wavelengths\u003c\/li\u003e\n\u003cli\u003e≥OD5 blocking from 200-1100nm to suppress star halos\u003c\/li\u003e\n\u003cli\u003e2-inch mounted format with 1.85mm glass thickness\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 3nm Colour Magic Ultra Ha\/OIII E1 Filter - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Askar 3nm Colour Magic Ultra E1 filter isolates critical nebulae emission lines with its ultra-narrow 3.7nm Hydrogen-alpha and 4.0nm Oxygen-III bandpasses. It achieves a peak transmittance of 85% at both the 656.6nm and 500.7nm center wavelengths, maximizing signal capture from emission targets. With off-band blocking rated at ≥OD5 from 200-1100nm, this filter delivers exceptionally high-contrast images by suppressing light pollution, moonlight, and unwanted starlight.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDual-Bandpass Imaging with 85% Peak Transmittance\u003c\/h3\u003e\n\u003cp\u003eDesigned for one-shot color cameras, the Ultra E1 captures the two most important emission lines simultaneously, drastically reducing total imaging time. By passing light at both 656.6nm (Ha) and 500.7nm (OIII) with 85% efficiency, you gather data for both the red and blue-green structures of targets like the Veil Nebula or the Rosette Nebula (NGC 2237) in a single set of exposures. This dual-band approach streamlines your workflow without compromising signal strength.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e3.7nm \u0026amp; 4.0nm Bandwidths for Extreme Light Pollution Rejection\u003c\/h3\u003e\n\u003cp\u003eThe defining feature of this filter is its extremely narrow full-width at half-maximum (FWHM). The 3.7nm band for Ha and 4.0nm for OIII aggressively reject unwanted light, including severe urban light pollution and natural skyglow. This surgical isolation of the nebula's signal creates a jet-black sky background, making faint, wispy details pop with dramatic contrast even from city backyards.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOD5 Blocking and 30\" Parallelism for Halo-Free Stars\u003c\/h3\u003e\n\u003cp\u003eOptical precision extends beyond the passbands. The filter provides ≥OD5 blocking across the wide 200-1100nm spectrum, ensuring that stray UV and IR light, which can cause halos on bright stars, never reaches the sensor. A parallelism of 30 arcseconds guarantees the filter will not introduce distortions or degrade the sharpness of your optical system, maintaining pinpoint stars across the field of view.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eAskar 3nm Ultra vs. Wider Dual-Band Filters: Contrast and Star Size\u003c\/h3\u003e\n\u003cp\u003eCompared to filters with 7nm or wider bandpasses, the Askar 3nm Ultra E1 offers a significant advantage in signal-to-noise ratio under light-polluted skies. The trade-off for this extreme contrast is a slight reduction in star brightness and potentially longer sub-exposure times to achieve the same signal level.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAskar 3nm Ultra E1:\u003c\/strong\u003e Delivers maximum nebula contrast by eliminating more background light. It is the superior choice for imaging from Bortle 7-9 locations or during bright moon phases.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWider Dual-Band Filters:\u003c\/strong\u003e Capture signal faster and often produce smaller, more natural-looking stars, as very narrow filters can sometimes slightly bloat the brightest stars due to diffraction effects. They are excellent for dark sky sites where light pollution is less of a concern.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar 3nm Ultra E1 filter effective in Bortle 8 or 9 skies?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. The ultra-narrow 3.7nm and 4.0nm bandwidths are specifically designed for this purpose. The Askar Ultra E1 excels at isolating the specific wavelengths of light from emission nebulae while aggressively blocking the broad-spectrum glow from city lights, making it one of the most effective tools for imaging from heavily light-polluted areas.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Askar 3nm Ultra E1 filter perform on the Trifid Nebula (M20) with my f\/7 refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Askar Ultra E1 is an excellent choice for the Trifid Nebula (M20). It will cleanly separate the red hydrogen-alpha emission region from the blue-green oxygen-III structures with a one-shot color camera. In an f\/7 system, you won't have issues with band-shifting, and the filter's high 85% transmittance will help capture good signal despite the slower focal ratio.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy are the bandwidths for the Askar Ultra E1 filter different for Ha (3.7nm) and OIII (4.0nm)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis is a deliberate optical design choice. The OIII emission line is often fainter than Ha in many nebulae, so providing a slightly wider 4.0nm bandpass allows more OIII signal to be collected, helping to balance the final color image. The Ha line is typically stronger, so a tighter 3.7nm band can be used for maximum contrast without sacrificing too much signal.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a monochrome camera to use the Askar 3nm Ultra E1 filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this filter is specifically designed for use with \u003cstrong\u003eone-shot color (OSC) cameras\u003c\/strong\u003e. It passes both red (Ha) and blue-green (OIII) light simultaneously, which are then captured by the corresponding pixels on your color sensor to create a rich color image with minimal processing effort.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the ≥OD5 blocking specification mean for my images?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eOD5 (Optical Density 5)\u003c\/strong\u003e means the filter blocks at least 99.999% of unwanted light outside its designated passbands. For astrophotography, this is critical for preventing halos around bright stars, which are often caused by out-of-focus UV and Infrared light that your telescope's optics were not designed to correct. This deep blocking ensures clean, high-contrast results.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 2\" Askar Ultra E1 filter work with a full-frame sensor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the 2-inch mounted format is designed to be large enough to fully illuminate full-frame sensors (36mm x 24mm) without vignetting, assuming it is placed correctly in the optical train, such as in a filter drawer or wheel close to the sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFWHM (Full-Width Half-Maximum)\u003c\/td\u003e\n\u003ctd\u003eHa: 3.7nm ± 0.3nm \/ OIII: 4.0nm ± 0.3nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCenter Wavelength (CWL)\u003c\/td\u003e\n\u003ctd\u003e656.6nm (Ha) \u0026amp; 500.7nm (OIII)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003e≥85%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOff-Band Blocking\u003c\/td\u003e\n\u003ctd\u003e≥OD5 (Optical Density 5) @ 200-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGlass Thickness\u003c\/td\u003e\n\u003ctd\u003e1.85 ± 0.05mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Finish\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30 arcseconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar 3nm Colour Magic Ultra Ha\/OIII E1 Filter - 2\"\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eProtective Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software \u0026amp; Drivers\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":50344440856861,"sku":"ASK-ASKAR2DBE1","price":847.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-Colour-Magic-E1-Filter.jpg?v=1757644549"},{"product_id":"askar-3nm-colour-magic-ultra-oiii-sii-e1-filter-2","title":"Askar 3nm Colour Magic Ultra OIII\/SII E2 Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDual-bandpass design captures OIII (500.7nm) and SII (672nm) simultaneously\u003c\/li\u003e\n\u003cli\u003eNarrow 3.7nm (OIII) and 4.0nm (SII) FWHM for high-contrast imaging\u003c\/li\u003e\n\u003cli\u003ePeak transmittance of 85% ensures high signal throughput\u003c\/li\u003e\n\u003cli\u003eDeep ≥OD5 blocking from 200-1100nm eliminates unwanted light pollution\u003c\/li\u003e\n\u003cli\u003eStandard 2\" filter format with 1.85mm substrate thickness\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 3nm Colour Magic Ultra OIII\/SII E2 Filter - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Askar 3nm Colour Magic Ultra OIII\/SII E2 Filter is engineered to solve a common problem for color camera imagers: capturing the full Hubble Palette. This dual-bandpass filter isolates nebula emissions at 500.7nm (OIII) and 672nm (SII) with narrow 3.7nm and 4.0nm bandpasses, respectively. With a peak transmittance of 85% and deep OD5 blocking across the 200-1100nm spectrum, this filter allows you to gather the missing Sulfur-II data needed for SHO compositions, even from light-polluted locations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe 672nm + 500.7nm Solution for Color Camera SHO Imaging\u003c\/h3\u003e\n\u003cp\u003eWhile standard duo-narrowband filters for color cameras typically capture Hydrogen-alpha and Oxygen-III, they leave out the critical Sulfur-II signal. The Askar Ultra E2 filter is designed specifically to fill this gap. By passing light at 672nm (SII) and 500.7nm (OIII), it allows you to collect the remaining two channels for a full SHO dataset without a filter wheel or monochrome camera.\u003c\/p\u003e\n\u003cp\u003eCombine the data from this filter with Hydrogen-alpha data (captured separately or with an Hα\/OIII filter) to unlock vibrant, detailed SHO images. This approach makes the celebrated Hubble Palette accessible and efficient for anyone using a one-shot-color astronomy camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e3.7nm \u0026amp; 4.0nm Bandpasses for Maximum Contrast\u003c\/h3\u003e\n\u003cp\u003eThis filter achieves its high contrast through extremely narrow full-width at half-maximum (FWHM) values: 3.7nm for OIII and 4.0nm for SII. These tight bandpasses aggressively reject streetlights, moonlight, and natural skyglow, causing faint nebula structures to stand out against a dark background. The ≥OD5 blocking from 200nm to 1100nm ensures no out-of-band wavelengths contaminate the image.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePeak Transmittance (85%):\u003c\/strong\u003e Despite the narrow bandpasses, the filter allows 85% of the crucial OIII and SII light to reach your sensor, preventing excessively long exposure times.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHalo Control:\u003c\/strong\u003e As part of Askar's \"Ultra\" series, this filter is optimized to minimize halos around bright stars, a common issue with narrowband filters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrecision Substrate:\u003c\/strong\u003e The filter is built on a glass substrate with a parallelism of 30 arcseconds, maintaining the sharpness of your optical system.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the primary purpose of the Askar Ultra E2 OIII\/SII filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Askar Ultra E2 is a specialized dual-narrowband filter designed for \u003cstrong\u003ecolor camera users\u003c\/strong\u003e who want to capture images in the Hubble Palette (SHO). It isolates the Oxygen-III (OIII) and Sulfur-II (SII) emission lines, allowing you to collect the \"S\" and \"O\" channels to complement your Hydrogen-alpha (\"H\") data.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I create an SHO image with the Askar Ultra E2 and a color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou will need to capture two sets of images. First, use a filter that passes Hydrogen-alpha (like an L-eXtreme, L-eNhance, or a dedicated Hα filter) to get your \"H\" data. Second, use this Askar Ultra E2 filter to capture your \"S\" and \"O\" data simultaneously. In post-processing, you will split the channels from both images and combine them using a tool like PixInsight's ChannelCombination to assign Hα to Red, SII to Green, and OIII to Blue (or any variation you prefer).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Askar Ultra E2 filter with a monochrome camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile it is designed for color cameras, you can use it with a monochrome camera. However, because it passes both OIII and SII light at the same time, you cannot separate the two signals onto the mono sensor. For monochrome imaging, using individual OIII and SII filters is the standard and more flexible approach.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy does the Askar Ultra E2 filter have 3.7nm and 4.0nm bandpasses instead of just \"3nm\"?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \"3nm\" is a class or series designation. The actual measured FWHM is \u003cstrong\u003e3.7nm ± 0.3nm for OIII\u003c\/strong\u003e and \u003cstrong\u003e4.0nm ± 0.3nm for SII\u003c\/strong\u003e. These precise, ultra-narrow bandpasses are what provide the exceptional contrast and light pollution rejection by isolating the specific nebula emission lines from background skyglow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow would the Askar Ultra E2 filter perform on the Wizard Nebula (NGC 7380) from a city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Wizard Nebula (NGC 7380) is rich in all three SHO gasses. From a city, the Askar Ultra E2 filter's narrow 3.7nm\/4.0nm bandpasses would be highly effective at cutting through light pollution to reveal the intricate structures in the OIII and SII regions. It would darken the sky background significantly, increasing the contrast and making the faint nebulosity visible in your exposures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Askar Ultra E2 filter work well with my fast f\/4 telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eUltra-narrowband filters like this one can experience some band-shifting with very fast optical systems (typically f\/4 and below). While it will still provide a significant contrast boost, you may see a slight reduction in transmission compared to its peak 85% rating. The filter's performance is optimal for systems at f\/4.5 and slower, but it remains a powerful tool for light pollution suppression even on faster scopes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFWHM (OIII)\u003c\/td\u003e\n\u003ctd\u003e3.7nm ± 0.3nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFWHM (SII)\u003c\/td\u003e\n\u003ctd\u003e4.0nm ± 0.3nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCenter Wavelength (CWL)\u003c\/td\u003e\n\u003ctd\u003e500.7nm (OIII) \u0026amp; 672nm (SII)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003e85%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Property\u003c\/td\u003e\n\u003ctd\u003e≥OD5 @ 200-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e1.85 ± 0.05mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Finish\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30″\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar 3nm Colour Magic Ultra OIII\/SII E2 Filter - 2\"\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eProtective Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software \u0026amp; Drivers\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":50344442036509,"sku":"ASK-ASKAR2DBE2","price":847.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-Colour-Magic-E2-Filter.jpg?v=1757644814"},{"product_id":"optolong-l-synergy-7nm-sii-oiii-dual-narrowband-filter","title":"Optolong L-Synergy 7nm SII\/OIII Dual Narrowband Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eCaptures Sulfur-II and Oxygen-III Emission Lines Simultaneously\u003c\/li\u003e\n\u003cli\u003eEngineered for Hubble Palette (SHO) Imaging with Color Cameras\u003c\/li\u003e\n\u003cli\u003eStrict 7nm Bandpass for High-Contrast Views in Light Pollution\u003c\/li\u003e\n\u003cli\u003eDesigned to Complement Standard Ha\/OIII Dual-Band Filters\u003c\/li\u003e\n\u003cli\u003eIon-Assisted Coatings for Durability and Wavelength Stability\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eOptolong L-Synergy 7nm SII\/OIII Dual Narrowband Filter\u003c\/h2\u003e\n\u003cp\u003eThe Optolong L-Synergy 7nm SII\/OIII Dual Narrowband Filter is a specialized tool designed to unlock Hubble Palette (SHO) astrophotography for color camera users. By isolating the Sulfur-II and Oxygen-III emission lines within a tight 7nm bandpass, this filter captures the two signals that standard dual-band filters miss. When combined with data from a traditional Ha\/OIII filter, the L-Synergy enables you to produce full three-channel narrowband images without investing in a monochrome camera and filter wheel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe L-Synergy Concept: SHO Imaging with a 7nm Color Camera Filter\u003c\/h3\u003e\n\u003cp\u003eTraditional SHO imaging requires a monochrome camera and three separate filters for Hydrogen-alpha, Sulfur-II, and Oxygen-III. The L-Synergy filter provides a more accessible path by targeting the missing data for a one-shot-color sensor. Paired with an existing Ha\/OIII filter, this 7nm SII\/OIII filter completes the dataset, allowing you to separate and process all three signals to create vibrant Hubble Palette composites.\u003c\/p\u003e\n\u003cp\u003eThis dual-filter strategy dramatically simplifies both the hardware required and the post-processing workflow. By capturing strong, distinct signal for both SII and OIII, the raw data is cleaner and requires less aggressive stretching or gradient removal, leading to a more natural final image with minimal effort.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eIsolating Sulfur and Oxygen: A 7nm Bandpass for Maximum Contrast\u003c\/h3\u003e\n\u003cp\u003eThe filter's strict 7nm bandpass is the key to its high-contrast imaging. This narrow window transmits nearly all light from the targeted SII and OIII emission lines while aggressively blocking out light pollution, moonlight, and airglow. This selective transmission results in a significantly darker sky background, making faint nebular structures stand out with enhanced detail and signal-to-noise ratio, even from urban or suburban locations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eIon-Assisted Deposition Coatings for Wavelength Stability\u003c\/h3\u003e\n\u003cp\u003eOptolong utilizes an advanced ion-assisted deposition coating process to manufacture the L-Synergy filter. This technique produces a hard, scratch-resistant surface and ensures the central wavelength of the filter does not shift due to temperature changes during an imaging session. This stability guarantees that your filter consistently captures the intended emission lines, preventing signal loss and maintaining color fidelity throughout the night.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eL-Synergy Method vs. Traditional Monochrome SHO Imaging\u003c\/h3\u003e\n\u003cp\u003eChoosing an imaging strategy involves trade-offs between cost, complexity, and ultimate signal purity. The L-Synergy method offers a compelling alternative to a full monochrome setup.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMonochrome SHO Advantage:\u003c\/strong\u003e A monochrome camera with dedicated filters offers the highest possible resolution and signal sensitivity, as it avoids the light loss inherent in a color camera's Bayer matrix. It remains the gold standard for scientific-grade data.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eL-Synergy Advantage:\u003c\/strong\u003e This method delivers results that are comparable to monochrome for a fraction of the cost and complexity. It allows you to use your existing DSLR or color CMOS camera, avoiding the need for a new camera, electronic filter wheel, and a full set of narrowband filters.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Optolong L-Synergy filter create Hubble Palette images with a color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe L-Synergy filter captures the \u003cstrong\u003eSulfur-II (SII) and Oxygen-III (OIII)\u003c\/strong\u003e signals. You use it in conjunction with a separate Ha\/OIII filter. By combining the data from both filters, you can isolate the Ha, SII, and OIII channels in post-processing and assign them to the Red, Green, and Blue channels of a final image to create the classic SHO Hubble Palette.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat other filter do I need to use with the Optolong L-Synergy?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eTo capture a complete SHO dataset, you need to pair the L-Synergy (SII\/OIII) filter with a standard dual-band filter that captures \u003cstrong\u003eHydrogen-alpha (Ha) and Oxygen-III (OIII)\u003c\/strong\u003e, such as the Optolong L-eNhance or L-eXtreme.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Optolong L-Synergy 7nm filter work well with my fast telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis filter is optimized for telescope systems with focal ratios of \u003cstrong\u003ef\/3.3 and slower\u003c\/strong\u003e. Using it with faster optical systems (e.g., f\/2) may cause a shift in the filter's bandpass, leading to reduced signal transmission and a potential loss of performance. For the best results, it should be used within its recommended focal ratio range.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Optolong L-Synergy filter improve imaging from a light-polluted city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe filter's tight \u003cstrong\u003e7nm bandpass\u003c\/strong\u003e blocks out the broad-spectrum light common to urban light pollution (like sodium and mercury vapor lamps) and natural skyglow. It only allows the specific light from emission nebulae to pass through, dramatically increasing contrast and revealing faint details that would otherwise be washed out.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong L-Synergy to image the Wolf-Rayet nebula WR134?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. WR134 in Cygnus is an excellent target for the L-Synergy filter because its expanding shell is extremely rich in Oxygen-III, with some Sulfur-II signal as well. This filter is ideal for capturing the intricate blue-green arc of OIII that defines this object, which is often faint with other filter types.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow would the Optolong L-Synergy perform on the Heart Nebula (IC 1805)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Heart Nebula is another prime target. While known for its strong Hydrogen-alpha signal (which you'd capture with an Ha\/OIII filter), it also contains significant regions of Sulfur-II and Oxygen-III. The L-Synergy filter will capture the data needed to add the golden hues of SII and the teal tones of OIII, transforming the typically red nebula into a full, multi-colored Hubble Palette image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/optolong-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eOptolong 3-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Optolong","offers":[{"title":"Default Title","offer_id":50399317033245,"sku":"OPT-LSYNERGY","price":432.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-L-Synergy-Filter-1.jpg?v=1758936099"},{"product_id":"svbony-sv220-7nm-ha-oiii-dual-band-filter","title":"SVBONY SV220 7nm Ha\/OIII Dual-Band Filter","description":"","brand":"SVBONY","offers":[{"title":"1.25\" Round Mounted","offer_id":52145332683037,"sku":"SV-W9172A","price":104.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":52145332715805,"sku":"SV-W9172b","price":170.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-SV220-7nm-Ha-OIII-Dual-Band-Filter.png?v=1784391995"},{"product_id":"svbony-sv220-3nm-h-alpha-and-oiii-dual-narrowband-filter","title":"SVBONY SV220 3nm H-Alpha \u0026 OIII Dual Narrowband Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e\n\u003cstrong\u003e3nm Dual-Bandpass:\u003c\/strong\u003e Isolates H-Alpha (656.3 nm) and OIII (500.7 nm) emission lines with extreme prejudice against light pollution.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e≥85% Peak Transmittance:\u003c\/strong\u003e Captures maximum signal from faint nebulae by allowing more than 85% of target light to reach the sensor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2-inch Mounted Format:\u003c\/strong\u003e Standard Φ50.8mm cell with M48x0.75mm threads for compatibility with most filter wheels and camera nosepieces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e44mm Clear Aperture:\u003c\/strong\u003e Provides an unvignetted field for full-frame sensors, ensuring even illumination from edge to edge.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOD5 Blocking Depth:\u003c\/strong\u003e Suppresses unwanted wavelengths from 300nm to 1050nm with an optical density of 5, delivering a jet-black sky background.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eNarrowband Filter 3nm H-Alpha \u0026amp; OIII SV220 2inch\u003c\/h2\u003e\n\u003cp\u003eThe SVBONY SV220 Narrowband Filter isolates the two most critical deep-sky emission lines with a tight 3nm bandpass centered at 656.3 nm for H-Alpha and 500.7 nm for OIII. This 2-inch filter achieves ≥85% peak transmittance for both wavelengths while its 44mm clear aperture eliminates vignetting on full-frame sensors. Mounted in a 7mm thick aluminum cell with standard M48x0.75mm threads, it delivers extreme contrast by blocking unwanted light with an average optical density of 5 across the 300-1050nm spectrum.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDual-Band 3nm Optics: Isolate H-Alpha and OIII with 85% Transmission\u003c\/h3\u003e\n\u003cp\u003eThe core of the SV220 filter is its extremely narrow 3nm bandwidth. This design aggressively rejects light pollution, moonlight, and airglow, allowing only the specific light from ionized hydrogen (H-Alpha at 656.3 nm) and doubly ionized oxygen (OIII at 500.7 nm) to pass through. With an average peak transmittance of ≥85%, you capture maximum signal from emission nebulae, revealing faint, intricate structures that would otherwise be lost in the skyglow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eFull-Frame Imaging: A 44mm Clear Aperture to Eliminate Vignetting\u003c\/h3\u003e\n\u003cp\u003eEngineered for modern large-format sensors, the SV220's 2-inch housing features a 44mm light transmission aperture. This generous clear aperture prevents the vignetting or dimming at the corners of the frame that can occur with smaller filters on full-frame cameras. The standard M48x0.75mm male thread ensures broad compatibility with dedicated astronomy cameras, filter wheels, and telescope focusers, providing a secure, tilt-free connection.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOD5 Blocking and λ\/4 Flatness: Suppressing Halos and Preserving Star Shape\u003c\/h3\u003e\n\u003cp\u003eBeyond the narrow bandpass, the SV220 uses a substrate with a transmitted wavefront of λ\/4 or better and parallelism of 30 arcseconds, ensuring that stars remain sharp and round. Multi-layer anti-reflection and anti-halo coatings, combined with an average OD5 blocking depth from 300nm to 1050nm, virtually eliminate halos around bright stars and produce a clean, high-contrast background. The filter is constructed from a 2.0mm thick substrate housed in a lightweight 12.5g 6061T aluminum cell for durability.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSV220 Dual-Band vs. Mono Filters: Streamlining Your Imaging Sessions\u003c\/h3\u003e\n\u003cp\u003eFor one-shot-color (OSC) camera users, a dual-band filter like the SV220 offers a significant workflow advantage over a monochrome camera with a filter wheel and separate H-alpha and OIII filters. While a mono setup provides the ultimate in data control, the SV220 allows you to capture both critical emission lines simultaneously, cutting your total imaging time in half without swapping filters. This is especially valuable on nights with limited clear skies or when imaging targets that are only visible for a few hours.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main advantage of the SVBONY SV220's 3nm dual-band design?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary advantage is \u003cstrong\u003eextreme contrast and efficiency\u003c\/strong\u003e. The ultra-narrow 3nm bandwidth isolates the key H-Alpha (656.3 nm) and OIII (500.7 nm) wavelengths, aggressively blocking light pollution. By capturing both bands at once, it dramatically reduces the imaging time required compared to using separate monochrome filters, making it ideal for OSC camera users.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the SV220 2-inch filter work with my full-frame camera and filter wheel?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The SVBONY SV220 is designed specifically for this application. It uses a standard 2-inch mounted cell (Φ50.8mm) with M48x0.75mm threads, which is the standard for most 2-inch filter wheels and camera nosepieces. Its 44mm clear aperture is large enough to fully illuminate full-frame sensors without causing vignetting.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the SV220 3nm filter perform on the Orion Nebula (M42) from a light-polluted suburb?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SV220 is ideal for this scenario. The Orion Nebula (M42) is rich in both H-Alpha and OIII emission. The filter's 3nm bandpass will reject nearly all city light, revealing the faint, extended nebulosity of the outer loops and the intricate detail within the Trapezium region that is normally washed out by skyglow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the SVBONY SV220 filter with my fast f\/4 Newtonian telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile you can, be aware of a potential trade-off. Very narrow filters like this 3nm model can experience a slight \"band-shift\" with very fast optical systems (typically f\/4 and below). This means the filter's center wavelength can shift slightly, potentially reducing transmission. For optimal results with this filter, systems of f\/4.5 or slower are recommended, but it can still yield excellent results at f\/4, especially on bright targets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the OD5 blocking depth on the SV220 filter mean for my images?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eOD5 means Optical Density 5\u003c\/strong\u003e, which is a measure of how well the filter blocks unwanted light. It signifies that the filter allows only 1\/100,000th of the light outside its bandpass to get through. This deep blocking across the 300-1050nm range is critical for creating a dark, high-contrast background and preventing sensor bloat from bright stars and near-infrared light.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the SV220 H-Alpha \u0026amp; OIII filter suitable for imaging galaxies like Andromeda (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eGenerally, no. Galaxies like the Andromeda Galaxy (M31) are broadband targets, meaning their light comes from stars emitting across the entire visible spectrum. A narrowband filter like the SV220 will block almost all of this light. It is specifically designed for \u003cstrong\u003eemission nebulae\u003c\/strong\u003e, such as the North America Nebula (NGC 7000) or the Veil Nebula (NGC 6960), which glow brightly at the H-Alpha and OIII wavelengths.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Size\u003c\/td\u003e\n\u003ctd\u003e2 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Dimensions\u003c\/td\u003e\n\u003ctd\u003eΦ50.8 × 7 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThreads\u003c\/td\u003e\n\u003ctd\u003eM48 × 0.75 mm (Male)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandwidth (FWHM)\u003c\/td\u003e\n\u003ctd\u003eH-alpha: 3±1 nm, OIII: 3±1 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCenter Wavelengths\u003c\/td\u003e\n\u003ctd\u003eH-alpha: 656.3 nm, OIII: 500.7 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003e≥85% Average\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e44 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e300–1050 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Depth\u003c\/td\u003e\n\u003ctd\u003eAverage OD5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Flatness\u003c\/td\u003e\n\u003ctd\u003e≤ λ\/4 Transmitted Wavefront\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30″\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e2.0 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003e6061T Aluminum Extrusion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e12.5g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eSV220 H-Alpha \u0026amp; OIII Dual Narrowband Filter (3nm \/ 2-inch)\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/svbony-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eSVBONY Warranty Policy\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SVBONY","offers":[{"title":"1.25\" Round Mounted","offer_id":52861233234205,"sku":"SV-W9198A","price":168.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":52861233266973,"sku":"SV-W9198B","price":350.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-Narrowband-Filter-3nm-H-Alpha-OIII-SV220-2inch-1_470fd306-4266-4f42-977d-da10a2a07ca4.jpg?v=1788659986"},{"product_id":"svbony-sv240-near-infrared-multi-narrowband-light-pollution-filter","title":"SVBONY SV240 Near-Infrared Multi-Narrowband Light Pollution Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDesigned for urban astrophotography with one-shot color cameras\u003c\/li\u003e\n\u003cli\u003ePasses H-Alpha, OIII, H-Beta, and Near-Infrared (NIR) wavelengths\u003c\/li\u003e\n\u003cli\u003ePeak transmittance over 95% for H-Alpha (656.3nm) and H-Beta (486.1nm)\u003c\/li\u003e\n\u003cli\u003eFeatures a wide 115nm FWHM bandpass in the NIR spectrum\u003c\/li\u003e\n\u003cli\u003eStandard 2-inch (M48x0.75) threaded cell\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eSvbony SV240 2\" NIR Multi Narrowband Filter\u003c\/h2\u003e\n\u003cp\u003eThe Svbony SV240 2\" NIR Multi Narrowband Filter is engineered for one-shot color imaging from light-polluted urban skies, capturing four critical spectral regions in a single exposure. This filter delivers peak transmittance of over 95% at H-Alpha (656.3nm) and H-Beta (486.1nm), and over 92% for OIII (495.9nm), while simultaneously opening a 115nm-wide window in the near-infrared with an average transmission greater than 95% between 830-870nm. Its 2mm substrate thickness and 1\/4λ surface parallelism ensure your optical system's sharpness is maintained, all within a standard M48x0.75 threaded cell.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTriple-Bandpass Design: Over 92% Transmission on Key Nebula Lines\u003c\/h3\u003e\n\u003cp\u003eThe core of the SV240 is its ability to isolate the three most important emission nebula spectral lines from the glare of city lights. With a peak transmission of \u0026gt;95% at H-Alpha (656.3nm), \u0026gt;92% at OIII (495.9nm), and \u0026gt;95% at H-Beta (486.1nm), the filter gathers maximum signal from your target. This high transmission is paired with aggressive blocking of common light pollution sources, achieving \u0026gt;OD4 suppression in the 560-620nm range, effectively eliminating the orange glow from sodium vapor lamps.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA 115nm Near-Infrared Window for Modern CMOS Sensors\u003c\/h3\u003e\n\u003cp\u003eUnlike traditional tri-band filters, the SV240 includes a fourth, wide passband in the near-infrared, spanning 830-870nm with an average transmission over 95%. This 115nm FWHM window is designed to leverage the high quantum efficiency of modern color CMOS sensors (like the Sony IMX585 and IMX464) in the NIR region. By capturing this additional signal, which is less affected by artificial light pollution, you can significantly boost the signal-to-noise ratio and contrast of your final image without complex processing. Note that imaging in the NIR band can sometimes introduce halos around bright stars, a known trade-off for the increased signal.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e2mm Substrate and 1\/4λ Parallelism for Sharp Stars\u003c\/h3\u003e\n\u003cp\u003eOptical precision is maintained by constructing the SV240 from a 2mm thick substrate with a surface parallelism of 1\/4λ. This ensures the filter will not introduce a significant focus shift or degrade the sharpness of your starfield, even in fast optical systems. The filter is housed in a standard 2-inch cell with M48x0.75 threads, making it compatible with most filter wheels, drawers, and camera nosepieces, while the 44mm clear aperture prevents vignetting on larger sensors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSvbony SV240 vs. SV220: Adding the H-Beta and NIR Bands\u003c\/h3\u003e\n\u003cp\u003eThe SV240 represents a significant evolution from a standard dual-bandpass filter like the Svbony SV220. While the SV220 is highly effective at isolating H-Alpha and OIII, the SV240 expands on this capability in two key ways.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eH-Beta Passband:\u003c\/strong\u003e The SV240 adds a dedicated passband for Hydrogen-Beta, crucial for capturing the full color and detail in objects like the Horsehead Nebula (Barnard 33) and California Nebula (NGC 1499).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNear-Infrared (NIR) Window:\u003c\/strong\u003e The SV240's primary advantage is its 115nm-wide NIR passband. This feature is specifically designed for modern color cameras highly sensitive to NIR light, allowing you to gather more signal data from a broader range of targets, including galaxies and star-forming regions, than is possible with the SV220.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Svbony SV240 filter's NIR band help with imaging the Orion Nebula (M42) from the city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Orion Nebula (M42) has strong emissions in H-Alpha, OIII, and H-Beta, which the \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e captures with \u0026gt;92% transmission. The added 115nm-wide NIR band captures additional signal from the star-forming regions deep within the nebula. Since urban light pollution has less impact in the NIR, this fourth band boosts your overall signal-to-noise ratio, revealing fainter details than a traditional tri-band filter could from the same location.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Svbony SV240 a good choice for my color camera with an IMX585 sensor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it is an excellent choice. The \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e was specifically designed with sensors like the Sony IMX585 in mind. These modern CMOS chips have very high quantum efficiency in the near-infrared. The filter's \u0026gt;95% average transmission in the 830-870nm range is designed to leverage this sensitivity, allowing you to collect significantly more data and achieve higher-contrast images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat's the difference between the SV240 and a standard UHC or CLS filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eUHC and CLS (City Light Suppression) filters are broadband filters that pass a much wider range of the spectrum, which can still let significant light pollution through. The \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e is a multi-narrowband filter with much tighter bandpasses (20nm and 24nm for OIII\/H-Beta and H-Alpha) that isolate specific emission lines with high precision. This results in much darker skies, higher contrast on nebulae, and the ability to image from more heavily light-polluted areas.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the SV240 filter with my 8\" f\/4 Newtonian for imaging galaxies like Andromeda (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. While galaxies like Andromeda (M31) are broadband targets, the \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e can still be very effective. It will capture the H-Alpha signal from the star-forming regions in the galaxy's spiral arms while suppressing city glow. The NIR band is also beneficial, as it captures signal from the older, redder star populations in the galactic core. The filter's 1\/4λ parallelism ensures it performs well with your fast f\/4 optics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy does the Svbony SV240 have three different FWHM values (24nm, 20nm, 115nm)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe different Full-Width Half-Maximum (FWHM) values correspond to the different passbands of the \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e filter. The 24nm and 20nm bandpasses are for the visible light emission lines (H-Alpha, H-Beta, OIII), providing a tight but manageable window for capturing nebula detail. The much wider 115nm FWHM is for the near-infrared (NIR) band, designed to gather as much signal as possible from this region where modern sensors are highly sensitive.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill I need to refocus when using the 2mm thick Svbony SV240 filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eSvbony SV240\u003c\/strong\u003e uses a 2mm thick substrate, which is a common standard. While any filter will shift the focal point slightly, a 2mm thickness is generally considered \"parfocal\" with many other modern filters. The shift will be minimal, but for critical sharpness, especially in fast telescopes, it is always best practice to check and refine focus after inserting any filter into the optical path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eSVBONY\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Name\u003c\/td\u003e\n\u003ctd\u003eMulti-Narrowband Filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eSV240\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e2-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThread\u003c\/td\u003e\n\u003ctd\u003eM48x0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e2mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWavelength Range\u003c\/td\u003e\n\u003ctd\u003e300-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFWHM\u003c\/td\u003e\n\u003ctd\u003e24nm \u0026amp; 20nm \u0026amp; 115nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003eT＞95%@656.3nm (H-α)\u003cbr\u003eT＞95%@486.1nm (H-β)\u003cbr\u003eT＞92%@495.9nm (OIII)\u003cbr\u003eT\u0026gt;85%@500.7nm (OIII)\u003cbr\u003eTavg\u0026gt;95%@830-870nm (NIR)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD5 @ 300-450nm\u003cbr\u003e\u0026gt;OD4 @ 560-620nm\u003cbr\u003e\u0026gt;OD2 @ 690-750nm\u003cbr\u003e\u0026gt;OD3 @ 940-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Parallelism\u003c\/td\u003e\n\u003ctd\u003e1\/4λ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSingle Thread\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e12.5g \/ 0.44oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/svbony-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eSVBONY 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SVBONY","offers":[{"title":"1.25\" Round Mounted","offer_id":52861237199133,"sku":"SV-W9191B","price":126.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Round Mounted","offer_id":52861237231901,"sku":"SV-W9191A","price":168.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-SV240-1-25-Multi-Narrowband-Filter-for-Urban-Astrophotography-1_9a989526-8ef6-408f-827e-43d86ba7f618.jpg?v=1788660312"},{"product_id":"svbony-sv260-5-bandpass-light-pollution-filter-2in","title":"SVBONY SV260 5-Bandpass Light Pollution Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e5-Bandpass broadband light pollution filter\u003c\/li\u003e\n\u003cli\u003e2-inch size with M48x0.75 thread\u003c\/li\u003e\n\u003cli\u003eOver 90% peak transmittance for high signal\u003c\/li\u003e\n\u003cli\u003eOD4 blocking of key light pollution bands\u003c\/li\u003e\n\u003cli\u003e44mm clear aperture to minimize vignetting\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eSvbony SV260 5 Bandpass Light Pollution Filter - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Svbony SV260 5 Bandpass Filter uses a multi-broadband design to reclaim the deep sky from city lights, achieving over 90% peak transmittance to preserve natural color in galaxies and star clusters. Its optical design provides greater than OD4 blocking on critical light pollution sources while maintaining a wide 300-1000nm wavelength range. The 2-inch cell features a full 44mm clear aperture, ensuring unvignetted coverage for large-format CMOS and CCD sensors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOD4 Blocking: Isolating Specific Light Pollution Sources\u003c\/h3\u003e\n\u003cp\u003eThe SV260's primary function is to surgically remove the most common wavelengths of artificial skyglow. It achieves an Optical Density (OD) of 4 or greater in the 350-400nm and 720-1100nm ranges, effectively blocking over 99.99% of unwanted light from these sources. Specific high-pressure sodium (Na) and mercury (Hg) vapor streetlight emissions are heavily suppressed, darkening the image background and dramatically increasing contrast on your target.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e5-Bandpass Design: Capturing Full-Spectrum Color at 90% Transmittance\u003c\/h3\u003e\n\u003cp\u003eUnlike narrowband filters that isolate single emission lines, the SV260 passes light in five distinct bands across the spectrum. This approach allows the faint, continuous spectra of broadband targets—such as the dusty arms of a galaxy or the blue glow of a reflection nebula—to reach your sensor. With a peak transmittance of over 90%, the filter maximizes the signal you want to capture, resulting in shorter total integration times and images with more accurate, vibrant color balance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOptical Build: A 44mm Clear Aperture for Modern Sensors\u003c\/h3\u003e\n\u003cp\u003eEngineered for modern imaging systems, the SV260 is built into a standard 2-inch filter cell with M48x0.75 threads for universal compatibility with filter wheels and camera nosepieces. The filter features a generous 44mm clear aperture, which is critical for preventing vignetting on cameras with APS-C or larger sensors. The 2mm substrate thickness maintains optical precision, with a surface parallelism of 1\/2λ to avoid introducing distortions into the light path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSV260 vs. Narrowband Filters: Choosing Natural Color Over Maximum Contrast\u003c\/h3\u003e\n\u003cp\u003eAn imager's choice of filter depends entirely on the target. The SV260 excels where narrowband filters fall short.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBroadband Targets:\u003c\/strong\u003e For galaxies like Andromeda (M31), reflection nebulae like the Pleiades (M45), and globular clusters like M13, the SV260 is the correct tool. It preserves the natural stellar colors and faint outer structures that narrowband imaging completely misses.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEmission Nebulae:\u003c\/strong\u003e For targets dominated by Hydrogen-alpha and Oxygen-III, such as the North American Nebula (NGC 7000), a dedicated narrowband or dual-band filter will provide higher contrast. The trade-off is the loss of natural star color and the need for complex color mapping in processing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe SV260 is designed for one-shot-color cameras, delivering a more authentic representation of the night sky directly from your data, making it an essential tool for capturing the full diversity of deep-sky objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of objects is the Svbony SV260 filter best for?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Svbony SV260 is a broadband filter designed for deep-sky objects that emit light across a wide spectrum. It is ideal for imaging \u003cstrong\u003egalaxies, star clusters (both open and globular), and reflection nebulae\u003c\/strong\u003e, where preserving natural color and capturing faint starlight is the primary goal.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the SV260 perform on the Andromeda Galaxy (M31) from a suburban backyard?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SV260 is an excellent choice for imaging M31 from light-polluted areas. It will significantly darken the sky background by blocking sodium and mercury vapor light, which increases the contrast of Andromeda's faint outer arms and dust lanes. Because it's a broadband filter, it will also preserve the true colors of the galaxy's core, star-forming regions, and surrounding starfield.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does OD4 blocking mean on the SV260 filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eOD4\u003c\/strong\u003e stands for \u003cstrong\u003eOptical Density 4\u003c\/strong\u003e. This is a logarithmic scale that measures how much light is blocked. An OD4 rating means the filter transmits only 1\/10,000th (or 0.01%) of the light at that specific wavelength. The SV260's OD4 blocking on key light pollution bands ensures that unwanted artificial skyglow is almost entirely eliminated from your images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eShould I use the Svbony SV260 or a UHC filter for the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis depends on your goal. The Orion Nebula (M42) has both strong emission regions (H-alpha, O-III) and a significant reflection component (the surrounding blue dust). A UHC (Ultra High Contrast) filter will provide more aggressive contrast on the glowing gas but will suppress the reflection nebula and alter star colors. The \u003cstrong\u003eSvbony SV260 will produce a more natural-looking image\u003c\/strong\u003e, capturing both the pinkish emission gas and the blue reflection dust with better color fidelity, making it a great choice for a true-color rendition of the entire complex.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 2-inch SV260 filter work with my full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the Svbony SV260 is well-suited for larger sensors. It features a \u003cstrong\u003e44mm clear aperture\u003c\/strong\u003e, which is larger than many standard 2-inch filters. This wide aperture helps prevent vignetting (darkening of the corners) on cameras with sensors up to and including full-frame format, provided the rest of your optical train is also properly illuminated.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Svbony SV260 replace the need for calibration frames?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, it does not. While the SV260 controls light pollution and improves your raw data, you must still shoot calibration frames. \u003cstrong\u003eDarks, biases, and especially flats are still required\u003c\/strong\u003e to correct for sensor noise, dust motes, and any remaining gradients to achieve the best possible final image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eSVBONY\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Name\u003c\/td\u003e\n\u003ctd\u003eMulti-Broadband Filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e2-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThread\u003c\/td\u003e\n\u003ctd\u003eM48x0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSingle Thread\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate Thickness\u003c\/td\u003e\n\u003ctd\u003e2mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmittance\u003c\/td\u003e\n\u003ctd\u003e90%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWavelength Range\u003c\/td\u003e\n\u003ctd\u003e300-1000nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking: UV\/IR\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD4 @ 350-400nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking: IR\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD4 @ 720-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking: Mercury (Hg)\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD2 @ 435.8nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking: Mercury (Hg)\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD1 @ 546.1nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking: Mercury (Hg)\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD3 @ 577nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking: Mercury (Hg)\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD3 @ 578.1nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking: Sodium (Na)\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD2 @ 589.6nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking: Neutral (Hg\/Na)\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD2 @ 589nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Parallelism\u003c\/td\u003e\n\u003ctd\u003e1\/2λ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e12.5g \/ 0.44oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/svbony-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eSVBONY Warranty Policy\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SVBONY","offers":[{"title":"2\" Round Mounted","offer_id":52861267214621,"sku":"SV-W9194A","price":175.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-SV260-5-Bandpass-Filter-Light-Pollution-Deep-Sky-Photography-1_eb6d63fd-a1dd-48d9-8cf5-41f43ca5546f.jpg?v=1788883781"},{"product_id":"player-one-anti-halo-pro-dual-band-2-inch-ha-oiii-filter","title":"Player One Anti-Halo PRO Dual-Band Ha\/OIII Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdvanced Halo Suppression:\u003c\/strong\u003e Specifically engineered to eliminate halos around even the brightest stars.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDual-Band Ha+OIII Design:\u003c\/strong\u003e Captures hydrogen-alpha and oxygen-III emission lines simultaneously, ideal for one-shot color cameras.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2-inch Mounted Format:\u003c\/strong\u003e Standard size for use in 2\" focusers, filter wheels, and filter drawers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProven on Fast Optics:\u003c\/strong\u003e Performance validated on an f\/4 Newtonian reflector, ensuring compatibility with demanding, fast-ratio systems.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section-center\"\u003e\n      \u003ch2\u003eAnti-Halo PRO Dual-Band 2″ Ha+OIII filter\u003c\/h2\u003e\n      \u003cp\u003eThe Anti-Halo PRO Dual-Band 2″ Ha+OIII filter is engineered to solve the single most persistent artifact in modern narrowband astrophotography: distracting halos around bright stars. Its effectiveness was proven in a demanding test on Vega, a magnitude 0 star, where a 120-second exposure with an 8\" f\/4 Newtonian produced a clean, halo-free stellar profile.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eTested on Vega: Zero Halos on a Magnitude 0 Star\u003c\/h3\u003e\n      \u003cp\u003eMany filters fail when imaging targets near bright stars. The Anti-Halo PRO was subjected to a worst-case scenario: a 120-second exposure of Vega, one of the brightest stars in the night sky, using a fast 8\" f\/4 Newtonian telescope. The result is a complete absence of the characteristic halo that plagues other narrowband and dual-band designs, proving its ability to maintain image integrity under the most challenging conditions.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eDual-Band Capture for Light-Polluted Skies\u003c\/h3\u003e\n      \u003cp\u003eDesigned for one-shot color cameras (DSLR, Mirrorless, and dedicated OSC astro cameras), this filter isolates the two most prominent emission nebula wavelengths—Hydrogen-alpha and Oxygen-III. This allows you to capture high-contrast nebula data from suburban skies in a single set of exposures, dramatically simplifying your imaging workflow and processing time compared to monochrome filter sets.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n    \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eAnti-Halo PRO vs. Conventional Filters: A Critical Difference\u003c\/h3\u003e\n      \u003cp\u003eWhile many filter manufacturers focus exclusively on achieving narrower bandpasses, this often comes at the cost of increased internal reflections, resulting in prominent halos. The Anti-Halo PRO prioritizes clean optical performance across the entire frame. It delivers the high-contrast, light-pollution-blocking benefits of a dual-band filter without forcing you to compromise on star quality, making it the superior choice for images containing bright, high-magnitude stars.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat makes the Anti-Halo PRO Dual-Band filter different from other Ha+OIII filters?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eIts primary design goal is \u003cstrong\u003ehalo suppression\u003c\/strong\u003e. While other filters focus solely on narrow bandpass, they can introduce severe halos around bright stars. The Anti-Halo PRO uses advanced coating techniques to eliminate these artifacts, ensuring clean stars even in fields with high-magnitude objects.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Anti-Halo PRO filter suitable for my DSLR or one-shot color camera?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, it is ideal for these cameras. The filter was tested using a Canon 700D DSLR. It passes both the red H-alpha and blue-green OIII wavelengths, allowing a standard color sensor to capture detailed nebula data in a single shot from light-polluted locations.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Anti-Halo PRO filter perform on a target like the Orion Nebula (M42)?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThis is an excellent use case. The Anti-Halo PRO filter will allow you to capture the faint outer nebulosity of M42 while keeping the bright stars of the Trapezium cluster sharp and free of distracting halos. This preserves the high dynamic range of the target without introducing artifacts.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the ideal focal ratio for the Anti-Halo PRO filter?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe filter has been proven to work exceptionally well on \u003cstrong\u003efast f\/4 systems\u003c\/strong\u003e, which are often the most challenging for filters due to the steep light cone angles. This indicates it will perform robustly on a wide range of telescope focal ratios, from fast Newtonians to slower refractors and SCTs.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIf I image the Veil Nebula (NGC 6960) near the star 52 Cygni, will this filter prevent halos?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, this is exactly the type of scenario the Anti-Halo PRO is designed for. It will suppress the halo from the bright star 52 Cygni, allowing the delicate, filamentary structure of the Witch's Broom Nebula to be captured cleanly without being overwhelmed by filter-induced artifacts.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Anti-Halo PRO filter for visual observing?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eNo, this is an imaging-only filter. Narrowband and dual-band filters have very restrictive bandpasses that are too dim for the human eye. They are designed for long-exposure astrophotography with a camera.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003ctable class=\"DAV-specifications\"\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cul class=\"DAV-grid\"\u003e\n    \u003cli class=\"DAV-grid-item\"\u003e\n      \u003cdiv\u003e\n        \u003cp class=\"DAV-item-title\"\u003eAnti-Halo PRO Dual-Band 2\" Filter\u003c\/p\u003e\n        \u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/li\u003e\n    \u003cli class=\"DAV-grid-item\"\u003e\n      \u003cdiv\u003e\n        \u003cp class=\"DAV-item-title\"\u003eProtective Case\u003c\/p\u003e\n        \u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cp\u003e\u003ca title=\"Player One 2-Year Warranty\" href=\"https:\/\/davidastro.com\/pages\/player-one-warranty-policy\" target=\"_blank\"\u003ePlayer One 2-Year Warranty\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Player One","offers":[{"title":"Default Title","offer_id":52913424597277,"sku":"POA-AHP-HO-2","price":699.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/PlayerOne-Anti-Halo-PRO-Dual-Band-2-Ha-OIII-filter-1_f6d48492-c19e-4962-b802-6c731d4e7240.jpg?v=1789090877"}],"url":"https:\/\/davidastro.com\/collections\/dual-band-filters.oembed","provider":"David Astro","version":"1.0","type":"link"}