{"title":"Optolong Dual-Band Filters","description":"\u003cp\u003eOptolong dual-band filters isolate two or more emission lines at once, which lets one-shot color cameras record nebulae through heavy light pollution or moonlight. The collection includes the Ha\/OIII L-Para 10nm, L-Extreme 7nm and L-Ultimate 3nm, the SII\/OIII L-Synergy 7nm, and the multi-band L-Enhance and L-Quad Enhance.\u003c\/p\u003e\u003cp\u003eNarrower bands give more contrast from the city but need longer exposures. Dual-Combo sets pair two filters to cover Ha, OIII and SII.\u003c\/p\u003e","products":[{"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":"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":"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":"optolong-l1-dual-combo-set","title":"Optolong L-Quad Enhance + L-Para L1 Dual-Combo Filter Set - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eL-Quad Enhance Filter:\u003c\/strong\u003e A quad-bandpass filter designed for balanced RGB color from broadband targets.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eL-Para L1 Filter:\u003c\/strong\u003e A dual-narrowband filter that isolates H-alpha and OIII emission lines for high-contrast detail.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBroadband-Narrowband Synergy:\u003c\/strong\u003e A two-filter system designed for capturing separate color and detail data to be combined in post-processing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptimized for Fast Optics:\u003c\/strong\u003e The L-Para filter maintains excellent contrast and anti-halo characteristics even in fast optical systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIon-Assisted Coatings:\u003c\/strong\u003e Precision coatings ensure durability, scratch resistance, and stable central wavelength performance regardless of temperature changes.\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-Quad Enhance + L-Para L1 Dual-Combo Filter Set - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Optolong L-Quad Enhance and L-Para L1 Dual-Combo Filter Set redefines color astrophotography by separating the capture of broadband color and narrowband detail into two specialized steps. This \"Broadband-Narrowband Synergy\" approach uses the L-Quad Enhance filter to acquire rich, natural RGB data from stars and galaxies, while the L-Para L1 dual-narrowband filter isolates the critical H-alpha and OIII emission lines that reveal the intricate structures within nebulae. By combining the data from both, you can produce images with vibrant, accurate color and deep, high-contrast details that are difficult to achieve with a single filter.\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-Quad Enhance: A Broadband Filter for True-Color Imaging\u003c\/h3\u003e\n\u003cp\u003eThe L-Quad Enhance is a quad-bandpass filter engineered to capture continuous-spectrum objects with superior color fidelity, even from light-polluted skies. It preserves the natural RGB color balance of targets like the Andromeda Galaxy (M31) or star clusters, improving overall contrast and making your subjects appear more vivid. This filter acts as the color foundation of your image, ensuring stars and galactic structures retain their true appearance.\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-Para: Isolating Hα \u0026amp; OIII for Maximum Nebula Detail\u003c\/h3\u003e\n\u003cp\u003eThe L-Para is a dual-narrowband filter that selectively passes H-alpha and Oxygen-III emission lines, the two most important wavelengths for revealing the structure of emission nebulae. It is designed to deliver excellent contrast and anti-halo performance, making it highly effective even with very fast optical systems. By isolating these specific signals, the L-Para captures the fine, filamentary details and ionized gas morphology in targets like the Lagoon Nebula (M8) or Horsehead Nebula (B33).\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 Synergy Workflow: Fusing Broadband Color with Narrowband Data\u003c\/h3\u003e\n\u003cp\u003eThis two-filter set enables a powerful imaging workflow. You use the L-Quad Enhance to shoot your primary RGB frames, capturing the broadband color data. You then switch to the L-Para to gather dedicated H-alpha and OIII data. In post-processing software like PixInsight or Photoshop, these separate data sets are combined, allowing the rich color from the L-Quad to be layered with the sharp, high-contrast details from the L-Para, creating a final image with exceptional depth and clarity.\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-Filter Strategy vs. a Single Multi-Bandpass Filter\u003c\/h3\u003e\n\u003cp\u003eWhile a single tri- or quad-band filter captures all wavelengths simultaneously, this dual-filter strategy offers greater control and optimization. You can dedicate more imaging time to capturing the faint Hα and OIII signals with the L-Para, without overexposing the broadband data. This separation allows you to independently control the signal-to-noise ratio of your color and detail layers, giving you more flexibility in processing to achieve a customized final result.\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 Coatings for Wavelength Stability and Durability\u003c\/h3\u003e\n\u003cp\u003eBoth Optolong filters are manufactured using an ion-assisted deposition coating process. This advanced technique creates a dense, durable, and scratch-resistant surface. Critically, it ensures the central wavelength (CWL) of the filter passbands does not shift with temperature changes during an imaging session, providing consistent, reliable data from dusk till dawn.\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 Optolong L-Quad + L-Para set over a single filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis set offers superior \u003cstrong\u003eprocessing flexibility\u003c\/strong\u003e. By capturing broadband color (with the L-Quad) and narrowband detail (with the L-Para) separately, you have independent control over each data stream. This allows you to optimize exposure times for faint nebula structures without compromising natural star color, leading to a more dynamic and detailed final image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow would I use the Optolong dual-filter set on the Trifid Nebula (M20)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Trifid Nebula is a perfect target for this set. You would use the \u003cstrong\u003eL-Quad Enhance\u003c\/strong\u003e filter to capture the blue reflection nebula and the surrounding starfield in true color. Then, you would switch to the \u003cstrong\u003eL-Para filter\u003c\/strong\u003e to gather deep exposures of the red H-alpha emission regions. Combining these in post-processing will showcase both the vibrant reflection and emission components with maximum detail.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the L-Para filter in this Optolong set suitable for my fast f\/2 RASA or Hyperstar system?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The L-Para filter is specifically designed to perform exceptionally well with fast optical systems. It maintains high transmission for the H-alpha and OIII lines while controlling halos, ensuring you can capture high-contrast, detailed images of nebulae even with very short focal ratios.\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 by itself for galaxies?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The L-Quad Enhance filter is an excellent standalone filter for broadband targets like galaxies and star clusters. It works as a light pollution filter that provides a much more natural color balance than typical multi-bandpass nebula filters, making it ideal for capturing continuous-spectrum objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of objects benefit most from the Optolong L-Para filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe L-Para filter excels on \u003cstrong\u003eemission nebulae\u003c\/strong\u003e. These are objects rich in ionized hydrogen (H-alpha) and oxygen (OIII). Prime targets include the Rosetta Nebula (NGC 2237), the Veil Nebula complex, and the North America Nebula (NGC 7000), where the filter will dramatically increase contrast and reveal faint structures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does \"CWL stability\" mean for these Optolong filters?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eCWL stands for Central Wavelength. \"CWL stability\" means the filter's passbands will not drift or change even as the ambient temperature fluctuates throughout the night. This is ensured by Optolong's advanced coating technology and results in more consistent and reliable data collection during long imaging sessions.\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":50341802574109,"sku":"OPT-L1-SET","price":558.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-L1-Dual-Combo-Set.jpg?v=1757558556"},{"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":"optolong-l-extreme-l-synergy-l2-dual-combo-filter-set-2","title":"Optolong L-Extreme + L-Synergy L2 Dual-Combo Filter Set - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eIncludes L-eXtreme (H-alpha + OIII) and L-Synergy (SII + OIII) filters\u003c\/li\u003e\n\u003cli\u003eEnables Hubble Palette (SHO) imaging with one-shot color cameras\u003c\/li\u003e\n\u003cli\u003eCaptures three key nebula emission bands across two filters\u003c\/li\u003e\n\u003cli\u003eDesigned for modern, fast focal ratio telescope systems\u003c\/li\u003e\n\u003cli\u003eAdvanced ion-assisted coatings suppress halos and light pollution\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-Extreme + L-Synergy L2 Dual-Combo Filter Set - 2\"\u003c\/h2\u003e\n      \u003cp\u003eThe Optolong L-Extreme + L-Synergy L2 Dual-Combo Filter Set is engineered to bring Hubble Palette imaging to one-shot color cameras, eliminating the need for a monochrome setup. This set combines the L-eXtreme (H-alpha and OIII) and L-Synergy (SII and OIII) dual-narrowband filters to isolate the three most important emission lines in deep-sky astrophotography. By capturing this data over two imaging sessions instead of one, you can create full SHO composite images with the operational simplicity of your existing color camera.\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\u003eUnlocking the Hubble Palette for Color Cameras with the Optolong L2 Set\u003c\/h3\u003e\n      \u003cp\u003eHistorically, creating SHO \"Hubble Palette\" images required a monochrome camera, a filter wheel, and three separate narrowband filters—a costly and complex setup. The Optolong L2 Dual-Combo set breaks this barrier by intelligently pairing two dual-bandpass filters, allowing your color camera to collect all the necessary data to assemble a full SHO image, from the hydrogen greens of the North American Nebula (NGC 7000) to the sulfur reds of the Pelican Nebula (IC 5070).\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\u003eThe L-eXtreme Filter: Capturing Ha and OIII in a Single Frame\u003c\/h3\u003e\n      \u003cp\u003eThe first filter in the set is the renowned L-eXtreme, which isolates the Hydrogen-alpha and Oxygen-III emission lines. These two signals represent the most dominant wavelengths in most emission nebulae. The filter transmits these specific bands while aggressively blocking light pollution and other unwanted signals, ensuring maximum contrast and signal-to-noise ratio for the H-alpha and OIII data channels in your final image.\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\u003eThe L-Synergy Filter: Adding the Critical SII Signal for SHO\u003c\/h3\u003e\n      \u003cp\u003eThe L-Synergy filter completes the trio by isolating the Sulfur-II and Oxygen-III emission lines. While you capture OIII data with both filters, the L-Synergy's primary role is to gather the crucial SII signal, which forms the red channel in a traditional Hubble Palette. This filter provides the final piece of the puzzle, enabling a three-channel color mapping (SII=Red, Ha=Green, OIII=Blue) from data captured with just two filters.\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\u003eOptolong L2 Dual-Combo vs. Monochrome SHO: A Simpler Workflow\u003c\/h3\u003e\n      \u003cp\u003eFor imagers who want SHO results without the expense and learning curve of a monochrome system, the L2 Dual-Combo set is the direct solution. A monochrome setup's advantage is its ultimate control over data, but it requires more accessories, longer total integration times, and complex processing. The L2 set preserves the simplicity of color imaging—fewer cables, no filter wheel, and a more streamlined workflow—while delivering access to the same creative color palette previously reserved for mono users.\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\u003eAdvanced Coatings for High-Contrast, Halo-Free Results\u003c\/h3\u003e\n      \u003cp\u003eBoth filters in the L2 set are manufactured using an ion-assisted deposition coating process. This technology ensures the filter coatings are physically durable, resistant to scratching, and stable against temperature shifts that can cause other filters to drift off-wavelength. The result is precise, consistent bandpass performance and excellent suppression of halos around bright stars, yielding clean, high-contrast data ready for processing.\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\"\u003eHow does the Optolong L2 Dual-Combo Set create a Hubble Palette image with a color camera?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe set allows you to capture all three essential narrowband channels (H-alpha, OIII, and SII) using a one-shot color camera. You use the \u003cstrong\u003eL-eXtreme filter\u003c\/strong\u003e to capture Ha and OIII data, then the \u003cstrong\u003eL-Synergy filter\u003c\/strong\u003e to capture SII and OIII data. In processing, you separate the color channels from both data sets to isolate the individual signals and then combine them into an SHO (SII=Red, Ha=Green, OIII=Blue) image.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the imaging process for the L2 Dual-Combo filters with my 8\" f\/4 Newtonian?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe process involves two separate imaging sessions on the same target. First, install the L-eXtreme filter and capture a series of sub-exposures. On a subsequent night (or after the first session), swap to the L-Synergy filter and capture another series of subs with similar total integration time. Because the set is designed for fast optical systems like your f\/4 Newtonian, you can gather significant signal efficiently.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Optolong L2 filters work well with my fast refractor?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, this filter set is specifically designed to perform well with fast telescope systems. The coatings and bandpass characteristics are engineered to maintain signal integrity and minimize artifacts even at steep light cones, making them an excellent match for modern fast refractors and astrographs.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main advantage of the Optolong L2 set over using a monochrome camera?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe primary advantage is \u003cstrong\u003ecost and simplicity\u003c\/strong\u003e. The L2 Dual-Combo set allows you to achieve SHO imaging without purchasing a separate monochrome camera, an electronic filter wheel, and a full set of LRGB and SHO filters. It leverages the color camera you already own, resulting in a much lower barrier to entry for creating Hubble Palette images.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I combine the data from the L-eXtreme and L-Synergy filters?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eAfter calibrating and stacking your images from each filter separately, you will have two master files. Using software like PixInsight or Siril, you can split the RGB channels of each master. The red channel from the L-eXtreme data becomes your H-alpha. The red channel from the L-Synergy data becomes your SII. The blue\/green channels from either can be used for your OIII, often by combining them for better signal. You then assign these three extracted grayscale images to the R, G, and B channels of a new color image.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eDo these Optolong filters help reduce halos around bright stars?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes. Both the L-eXtreme and L-Synergy filters are manufactured with advanced coating techniques that significantly suppress internal reflections. This technology is optimized to minimize the bright, distracting halos that can appear around high-magnitude stars in long narrowband exposures.\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":50923140808989,"sku":"OPT-L2-COMBO","price":796.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-L2Dual-Combo-Filter-Set.jpg?v=1770476463"}],"url":"https:\/\/davidastro.com\/collections\/optolong-dual-band-filters.oembed","provider":"David Astro","version":"1.0","type":"link"}