{"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":119.99,"currency_code":"USD","in_stock":true},{"title":"2\" Round Mounted","offer_id":52861233266973,"sku":"SV-W9198B","price":249.99,"currency_code":"USD","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","url":"https:\/\/davidastro.com\/fr-us\/products\/svbony-sv220-3nm-h-alpha-and-oiii-dual-narrowband-filter","provider":"David Astro","version":"1.0","type":"link"}