{"title":"Optolong Light Pollution Filters","description":"\u003cp\u003eOptolong light pollution filters are broadband filters that reduce sky glow from artificial lighting while keeping a natural color balance on stars and galaxies. The collection includes the L-Pro, the CLS and CLS-CCD, the Clear Sky filter, and an L-Pro + UHC clip filter kit for cameras that accept clip-in filters.\u003c\/p\u003e\u003cp\u003eUnlike narrowband or dual-band filters, they suit galaxies, star clusters and reflection nebulae as well as emission nebulae, for color imaging from suburban sites.\u003c\/p\u003e","products":[{"product_id":"optolong-l-pro-filter","title":"Optolong L-Pro Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eMulti-Bandpass Light Pollution Suppression\u003c\/li\u003e\n\u003cli\u003eEffective Spectrum from 380-750nm\u003c\/li\u003e\n\u003cli\u003eMaintains Natural Color Balance on Broadband Targets\u003c\/li\u003e\n\u003cli\u003eHigh Transmission on Major Nebula Emission Lines\u003c\/li\u003e\n\u003cli\u003eDurable Ion-Assisted Multi-Layer Coatings\u003c\/li\u003e\n\u003cli\u003eSurface Quality of 60\/40 per MIL-O-13830\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\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-Pro Filter\u003c\/h2\u003e\n\u003cp\u003eThe Optolong L-Pro Filter is engineered to reclaim the night sky from urban light pollution, operating across a 380-750nm spectrum and manufactured to a 60\/40 surface quality standard. Its multi-bandpass design selectively blocks the most common wavelengths of artificial light while transmitting the light from deep-sky objects, resulting in images with dramatically improved contrast and natural color rendition.\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\u003eSuppressing Light Pollution Across the 380-750nm Spectrum\u003c\/h3\u003e\n\u003cp\u003eThe core function of the L-Pro is to isolate and reject specific emission lines from artificial light sources. It effectively targets the dominant wavelengths produced by mercury vapor, high-pressure sodium, and low-pressure sodium streetlights, which are the primary contributors to skyglow. By filtering these specific pollutants within its 380-750nm operational range, the L-Pro darkens the sky background without altering the light from your astronomical target.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA Multi-Bandpass Design for Natural-Color Imaging\u003c\/h3\u003e\n\u003cp\u003eUnlike more aggressive filters that can produce a strong color cast, the L-Pro uses a balanced, multi-bandpass approach. This design preserves the natural colors of broadband targets like galaxies, reflection nebulae, and globular clusters. For imagers, this means less time spent on color correction in post-processing and a final result that more accurately represents the true colors of the object.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eHigh Transmission for Key H-Alpha and OIII Emission Lines\u003c\/h3\u003e\n\u003cp\u003eWhile excelling at broadband targets, the L-Pro also maintains high transmission for the most important emission nebula wavelengths. It passes critical lines including Hydrogen-alpha, Oxygen-III, Sulfur-II, and Hydrogen-beta. This allows you to capture the faint, glowing structures within objects like the Orion Nebula (M42) or the North American Nebula (NGC 7000) with enhanced contrast against the newly darkened sky.\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\u003eBuilt to a 60\/40 Military Surface Quality Standard\u003c\/h3\u003e\n\u003cp\u003eEach L-Pro filter is manufactured to a 60\/40 surface quality specification according to military standard MIL-O-13830, ensuring clear, artifact-free images. The glass undergoes an ion-assisted deposition coating process, which creates a durable, scratch-resistant surface. This advanced coating technology also ensures the filter's central wavelength remains stable, preventing passband shifts due to 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-Pro vs. UHC Filters: Choosing the Right Tool\u003c\/h3\u003e\n\u003cp\u003eA common question is how the L-Pro compares to an Ultra High Contrast (UHC) filter. A UHC filter offers a more aggressive approach, providing maximum contrast on emission and planetary nebulae by isolating just the OIII and H-beta lines. This comes at the cost of nearly all star color and renders it ineffective for broadband targets.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eChoose a UHC Filter\u003c\/strong\u003e for visual observing or imaging of emission nebulae from heavily light-polluted areas where maximizing contrast is the only goal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChoose the Optolong L-Pro\u003c\/strong\u003e when your targets include galaxies, reflection nebulae, or star clusters, or when preserving natural color is a priority. It is the more versatile, \"do-it-all\" light pollution filter for modern color cameras.\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-Pro different from other light pollution filters?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Optolong L-Pro is a \u003cstrong\u003emulti-bandpass filter\u003c\/strong\u003e designed for maximum color fidelity. Unlike narrowband or aggressive UHC filters that eliminate most star color, the L-Pro selectively blocks only the primary wavelengths of artificial light, preserving the natural color of broadband targets like galaxies and star clusters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong L-Pro filter suitable for visual use?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the L-Pro is effective for both visual observation and astrophotography. Visually, it darkens the sky background, making it easier to detect faint deep-sky objects from suburban locations. The improved contrast helps reveal subtle details in galaxies and nebulae that would otherwise be lost to skyglow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Optolong L-Pro filter affect my images of the Andromeda Galaxy (M31) from a suburban backyard?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Andromeda Galaxy is a perfect target for the L-Pro. The filter will significantly increase the contrast between M31's faint outer arms and the brightened suburban sky. Crucially, it will do so while preserving the natural blue and yellow hues of the galaxy's star populations, providing a much more detailed and aesthetically pleasing image than you could capture without a filter.\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-Pro to image emission nebulae like the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The L-Pro allows high transmission of the key emission lines that make up the Orion Nebula, including Hydrogen-alpha and Oxygen-III. It will suppress local light pollution, increasing the contrast and revealing fainter details in the nebula's structure while retaining natural star colors in the Trapezium cluster and surrounding field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Optolong L-Pro filter block infrared (IR) light?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the L-Pro filter effectively blocks infrared wavelengths. This is a key feature for astrophotography, as it means you can use it as your primary luminance (\"L\") filter with a monochrome CCD or CMOS camera without needing a separate IR-cut filter, which simplifies your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a different Optolong L-Pro filter for my DSLR and my telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt depends on how you want to use it. The Optolong L-Pro is available in multiple formats to suit different setups:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" and 2\" Mounted:\u003c\/strong\u003e These thread directly into standard telescope eyepieces or camera nosepieces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClip-in Filters:\u003c\/strong\u003e These are designed for specific DSLR and mirrorless camera bodies (Canon, Nikon, Sony) and fit inside the camera, allowing you to use any camera lens.\u003c\/li\u003e\n\u003c\/ul\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\u003eSpectrum\u003c\/td\u003e\n\u003ctd\u003e380-750nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40 (Refer to MIL-O-13830)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable Options\u003c\/td\u003e\n\u003ctd\u003e1.25\" Mounted, 2\" Mounted, Clip for Canon EOS APS-C, Clip for Canon EOS Full Frame, Clip for Nikon Full Frame, Clip for Sony Full Frame, Clip for Canon EOS-R\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Function\u003c\/td\u003e\n\u003ctd\u003eMulti-Bandpass Light Pollution Suppression\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoating Technology\u003c\/td\u003e\n\u003ctd\u003eIon-Assisted Multi-Layer Coatings\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-Pro Filter (in selected format)\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eProtective Storage Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\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":44967780811037,"sku":"OPT-10201","price":199.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Mounted","offer_id":44967780843805,"sku":"OPT-10202","price":279.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Canon EOS APS-C","offer_id":44967780909341,"sku":"OPT-10203","price":349.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Canon EOS Full Frame","offer_id":44967780942109,"sku":"OPT-LPRO-EOS-FF","price":377.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Nikon Full Frame","offer_id":44967780974877,"sku":"OPT-LPRO-NIKON-FF","price":377.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Sony Full Frame","offer_id":44967781007645,"sku":"OPT-10208","price":377.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Canon EOS-R","offer_id":44967781040413,"sku":"OPT-10211","price":349.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Nikon Z Full Frame","offer_id":52942348484893,"sku":"OPT-LPRO-NK-Z","price":349.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Optolong-L-Pro-2inch__58386.1612893783.1280.1280.jpg?v=1684345839"},{"product_id":"optolong-clear-sky-filter","title":"Optolong Clear Sky Light Pollution Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eSuppresses common sources of urban light pollution\u003c\/li\u003e\n\u003cli\u003eEnhances contrast for deep-sky objects\u003c\/li\u003e\n\u003cli\u003eImproves natural color balance in astrophotography\u003c\/li\u003e\n\u003cli\u003eDurable, scratch-resistant Ion-assisted coatings\u003c\/li\u003e\n\u003cli\u003eAvailable in M77\/M82 lens thread and Nikon Z clip-in formats\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\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 Clear Sky Light Pollution Filter\u003c\/h2\u003e\n      \u003cp\u003eThe Optolong Clear Sky Light Pollution Filter is engineered to reclaim the natural contrast and color of the night sky from light-polluted locations. By selectively blocking the most common wavelengths of artificial lighting, this filter allows the faint light from nebulae and galaxies to stand out against a darker background. It utilizes advanced ion-assisted deposition coatings to ensure durability and stable performance, making it an essential tool for DSLR and mirrorless camera astrophotography in urban and suburban environments.\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\u003eRestoring Natural Sky Contrast from the City\u003c\/h3\u003e\n      \u003cp\u003eShooting from a city or suburb washes out faint deep-sky objects, blending them into a bright, hazy background. The Optolong Clear Sky filter targets and suppresses the spectral lines of common streetlights and artificial skyglow, effectively darkening the sky without altering the natural color of stars and galaxies. This process dramatically enhances the contrast between your target and the background, revealing detail that would otherwise be lost.\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\u003eIon-Assisted Coatings for Durability and Color Fidelity\u003c\/h3\u003e\n      \u003cp\u003eOptolong employs a sophisticated ion-assisted deposition coating process to create a filter that is both effective and resilient. This technology produces a hard, scratch-resistant surface and ensures the central wavelength of the filter remains stable regardless of temperature changes during an imaging session. The precision and homogeneity of these coatings result in high transmission of desirable wavelengths, preserving true-to-life color balance for a more natural final image.\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 Clear Sky Filter improve astrophotography from a city?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe Optolong Clear Sky Filter works by selectively blocking the most common wavelengths of light emitted by artificial sources like sodium and mercury-vapor streetlights. This darkens the sky background in your images, which significantly \u003cstrong\u003eincreases the contrast\u003c\/strong\u003e of celestial objects like galaxies and nebulae, making them stand out more clearly.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the difference between the Optolong Clear Sky filter and a stronger nebula filter like a UHC?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe Clear Sky filter is a \u003cstrong\u003ebroadband light pollution filter\u003c\/strong\u003e, designed to improve contrast while maintaining natural star color, making it great for galaxies and star clusters. A UHC (Ultra High Contrast) filter is a \u003cstrong\u003enarrowband filter\u003c\/strong\u003e that passes only specific emission lines (like H-Beta and OIII), resulting in a much darker sky but also a significant color cast. UHC filters are specialized for emission nebulae, while the Clear Sky filter is more versatile.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Optolong Clear Sky Filter change the color of stars in my images?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe filter is designed to produce a natural color balance with minimal color cast. While any filter that removes parts of the spectrum will have some effect, the Optolong Clear Sky filter aims to preserve the natural coloration of stars and broadband targets like galaxies, making color correction in post-processing much simpler than with more aggressive narrowband filters.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I choose between the lens thread and clip-in versions of the Optolong Clear Sky Filter?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eChoose the version based on your equipment and needs:\u003c\/p\u003e\n    \u003cul\u003e\n      \u003cli\u003e\n\u003cstrong\u003eLens Thread (M77, M82):\u003c\/strong\u003e This type screws directly onto the front of your camera lens, just like a standard UV filter. It's ideal if you primarily use one or two lenses with the same filter thread size.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eClip-in Filter:\u003c\/strong\u003e This version fits inside the camera body, just behind the lens mount. This allows you to use the filter with \u003cstrong\u003eany lens\u003c\/strong\u003e compatible with your camera body (e.g., Nikon Z mount), which is more economical if you frequently switch between different lenses.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong Clear Sky Filter to photograph the Andromeda Galaxy (M31) from a suburban backyard?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, absolutely. The Andromeda Galaxy (M31) is a perfect target for this filter. As a broadband object (a galaxy made of stars), it benefits greatly from the increased contrast the Clear Sky filter provides against a light-polluted suburban sky, helping to reveal its faint outer arms and dust lanes without distorting its natural color.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong Clear Sky Filter effective for shooting the Orion Nebula (M42) with a standard DSLR?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, the Optolong Clear Sky Filter is very effective for bright emission nebulae like the Orion Nebula (M42). It will help suppress local light pollution, making the faint, extended nebulosity more visible against a dark background while preserving the natural colors in the bright core and surrounding star field.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003ctable class=\"DAV-specifications\"\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003ctd\u003eAvailable Mounting Options\u003c\/td\u003e\n\u003ctd\u003eM77 Lens Thread, M82 Lens Thread, Clip-in for Nikon Z Full Frame\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":"M77 Lens Thread","offer_id":52941912113437,"sku":"OPT-10503","price":231.0,"currency_code":"CAD","in_stock":true},{"title":"M82 Lens Thread","offer_id":52941912146205,"sku":"OPT-10504","price":287.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Nikon Z Full Frame","offer_id":52941912178973,"sku":"OPT-CLEARSKY-NK-Z","price":139.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-Clear-Sky-Filter-Screw-on-Lens-1_70b48089-a026-41d6-a39c-0cb0db0499d1.jpg?v=1789592341"},{"product_id":"optolong-cls-filter","title":"Optolong CLS Light Pollution Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eSuppresses common light pollution sources\u003c\/li\u003e\n\u003cli\u003eAverage transmission greater than 90% on key nebula emission lines\u003c\/li\u003e\n\u003cli\u003eBlocks light pollution lines with \u0026gt;99% efficiency\u003c\/li\u003e\n\u003cli\u003e1.85mm thick optical glass substrate\u003c\/li\u003e\n\u003cli\u003eλ\/4 transmitted wavefront and 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\u003cli\u003eIn the Box\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 CLS Light Pollution Filter\u003c\/h2\u003e\n\u003cp\u003eThe Optolong CLS (City Light Suppression) filter restores contrast to your deep-sky views by blocking over 99% of common artificial light sources. Built on a 1.85mm optical glass substrate, it maintains a λ\/4 transmitted wavefront for sharp images while delivering over 90% transmission of critical nebula emission lines like H-alpha and OIII. With 30s parallelism, the filter introduces no optical distortions, making it a powerful tool for visual observers and imagers using color cameras or unmodified DSLRs under suburban 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\u003eTargeted Light Pollution Suppression: \u0026gt;99% Blocking of Sodium \u0026amp; Mercury Lines\u003c\/h3\u003e\n\u003cp\u003eThe core function of the Optolong CLS is to surgically remove the wavelengths associated with common streetlights. It achieves greater than 99% blocking of mercury vapor, high-pressure sodium, and low-pressure sodium vapor lamp emissions. This aggressive rejection of unwanted light darkens the sky background significantly, allowing the faint signal from your target to stand out in much higher contrast.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eHigh-Transmission Broadband Design: \u0026gt;90% Pass-Through on Key Emission Lines\u003c\/h3\u003e\n\u003cp\u003eWhile blocking unwanted light, the CLS filter maintains an average transmission of over 90% for the most important deep-sky wavelengths. This wide passband includes hydrogen-alpha (656nm), hydrogen-beta (486nm), oxygen-III (496nm and 500nm), and sulfur-II (672nm). By preserving the light from these emission nebulae, the filter reveals more detail and structure in objects like the Orion Nebula (M42) or the Lagoon Nebula (M8) without significantly altering natural star colors.\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\u003ePrecision-Coated 1.85mm Glass: λ\/4 Wavefront and 30s Parallelism\u003c\/h3\u003e\n\u003cp\u003eOptolong constructs the CLS filter from a 1.85mm thick slab of fine optical glass, ensuring mechanical stability and optical purity. Ion-assisted deposition coatings provide durability and prevent the central wavelength from shifting with temperature changes. The filter is polished to a transmitted wavefront of λ\/4 and a parallelism of 30 arcseconds, guaranteeing that it will not degrade the resolution of your telescope's optics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOptolong CLS vs. UHC Filters: Choosing the Right Tool for Your Sky\u003c\/h3\u003e\n\u003cp\u003eThe CLS is often compared to Ultra High Contrast (UHC) filters. The primary difference is the width of the passband.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptolong CLS Filter:\u003c\/strong\u003e Features a wider passband, making it more effective in mild to moderate light pollution. It preserves more natural star color and is a better general-purpose filter for a mix of objects, including reflection nebulae and star clusters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUHC Filter:\u003c\/strong\u003e Has a narrower passband, primarily focused on the H-beta and OIII lines. This provides more aggressive contrast on emission nebulae but can dim stars more significantly. It is often preferred for darker sites or areas with more severe light pollution where maximum rejection is needed.\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 CLS and a UHC filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eOptolong CLS filter\u003c\/strong\u003e has a wider bandpass, making it a \"broadband\" filter ideal for mild to moderate light pollution. It passes more of the visible spectrum, resulting in more natural star colors. A UHC filter is a \"narrowband\" filter with a tighter passband, offering higher contrast on emission nebulae but at the cost of dimming stars more, making it better suited for more heavily light-polluted skies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong CLS filter for imaging galaxies like Andromeda (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, but with limitations. Galaxies are broadband targets, meaning they emit light across the entire visible spectrum. The \u003cstrong\u003eOptolong CLS filter\u003c\/strong\u003e will increase the contrast between the galaxy and the skyglow, but it will also block some of the galaxy's own light. It can help bring out H-II regions in the spiral arms but may reduce the overall brightness of the galactic core.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Optolong CLS filter perform on the Orion Nebula (M42) from my suburban backyard with an 8\" SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eOptolong CLS filter\u003c\/strong\u003e is an excellent choice for this scenario. M42 is rich in hydrogen-alpha and oxygen-III emissions, which the filter transmits with over 90% efficiency. In your 8\" SCT, the filter will dramatically darken the suburban sky background, making the faint outer loops of the nebula visible and enhancing the contrast and detail within the Trapezium region.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong CLS filter suitable for an unmodified DSLR camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the \u003cstrong\u003eOptolong CLS filter\u003c\/strong\u003e is designed to work very well with color CMOS\/CCD cameras and unmodified DSLRs. Its passband includes the critical 656nm H-alpha line, which standard DSLRs are less sensitive to but still capture. The filter helps isolate this important wavelength from light pollution, improving the signal in your images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Optolong CLS filter make nebulae look brighter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this is a common misconception. No filter can increase an object's actual brightness. The \u003cstrong\u003eOptolong CLS filter\u003c\/strong\u003e works by increasing the *contrast* between the nebula and the night sky. It achieves this by selectively blocking light pollution, which makes the background darker, thereby making the nebula easier to see against it.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy does my Optolong CLS filter look like a mirror and change colors?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis is normal for an interference filter like the \u003cstrong\u003eOptolong CLS\u003c\/strong\u003e. The highly reflective appearance is due to the dielectric coatings that are precisely layered to reject specific wavelengths of light. The color will appear to shift depending on the viewing angle and ambient light, which is a sign that the coatings are functioning as designed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWARNING: Can I use the Optolong CLS filter for observing the Sun?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eAbsolutely not.\u003c\/strong\u003e The Optolong CLS filter is NOT a solar filter and is not designed for sun observation. Looking at the Sun with this filter, or any filter not explicitly designed for safe solar viewing, will cause immediate and permanent blindness.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eBroadband Light Pollution Suppression (CLS)\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\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\u003eAverage Transmission\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;90%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e400-700nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Depth\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;99% on light pollution lines\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmitted Wavefront\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\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eOptolong CLS Light Pollution Filter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eProtective Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\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":52941921288477,"sku":"OPT-11801","price":77.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Mounted","offer_id":52941921321245,"sku":"OPT-11802","price":119.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-CLS-City-Light-Suppression-broadband-filter-is-designed-to-improve-the-visibility-of-various-deepsky-objects-1_1622ccd9-042b-4aec-b31c-a974b2ff5095.jpg?v=1789592400"},{"product_id":"optolong-cls-ccd-filter","title":"Optolong CLS-CCD Light Pollution Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eBlocks \u0026gt;99% of primary light pollution emission lines\u003c\/li\u003e\n\u003cli\u003eAchieves \u0026gt;90% average transmission on key nebula wavelengths\u003c\/li\u003e\n\u003cli\u003eIntegrated 300-1100nm UV\/IR cut filter for color cameras\u003c\/li\u003e\n\u003cli\u003eλ\/4 transmitted wavefront and 30s parallelism for sharp stars\u003c\/li\u003e\n\u003cli\u003e1.85mm thick 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\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 CLS-CCD Light Pollution Filter\u003c\/h2\u003e\n\u003cp\u003eThe Optolong CLS-CCD Light Pollution Filter is engineered to reclaim contrast in your astrophotos by blocking over 99% of common light pollution sources while maintaining an average transmission greater than 90% on critical nebula emission lines. Its integrated 300-1100nm blocking range makes it a single-filter solution for color CCD and modified DSLR cameras, eliminating star bloat from infrared without needing a separate IR-cut filter. The 1.85mm optical glass substrate is polished to a λ\/4 transmitted wavefront, ensuring your system's resolution is not compromised.\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\u003eBlocking \u0026gt;99% of Sodium and Mercury Vapor Lines\u003c\/h3\u003e\n\u003cp\u003eThis filter's primary function is to surgically remove the wavelengths associated with urban skyglow. It achieves a blocking depth of over 99% for mercury vapor, high-pressure sodium, and low-pressure sodium vapor lamps—the most common sources of artificial light pollution. By rejecting this unwanted light, the background sky in your images becomes significantly darker, allowing the faint, complex structures of nebulae to stand out.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOver 90% Transmission on H-alpha, OIII, and SII\u003c\/h3\u003e\n\u003cp\u003eWhile aggressively blocking pollutants, the CLS-CCD maintains an average transmission rate (Tave) of over 90% across the most important emission lines for deep-sky objects. This high throughput applies to hydrogen-alpha (656nm), oxygen-III (496nm and 500nm), hydrogen-beta (486nm), and sulfur-II (672nm). The result is vibrant, high-contrast images of emission nebulae, planetary nebulae, and supernova remnants, with their natural colors 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\u003eThe CCD Advantage: Integrated 300-1100nm IR\/UV Cut for Color Sensors\u003c\/h3\u003e\n\u003cp\u003eThe \"CCD\" in the name signifies a critical feature: a built-in UV and IR cut filter covering a wide 300-1100nm range. Many color astronomy cameras and modified DSLRs have sensors that are sensitive to infrared light, which can cause bloated, unfocused stars if not filtered out. The CLS-CCD eliminates the need for a separate L-filter (luminance\/IR-cut), simplifying your imaging train and ensuring sharp, tight stars across the frame.\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\u003eCLS-CCD vs. Standard CLS: Why IR Cut Matters\u003c\/h3\u003e\n\u003cp\u003eThe key difference between the Optolong CLS-CCD and the standard visual CLS filter is the infrared blocking. While both filters suppress the same light pollution lines, the standard CLS allows infrared light to pass through. This makes it suitable for visual use or for monochrome cameras shooting with a separate filter wheel.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eChoose the CLS-CCD if:\u003c\/strong\u003e You use a one-shot-color (OSC) camera, a color CCD, or a modified DSLR. The integrated IR-cut is essential for preventing star bloat and achieving correct color balance without an extra filter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChoose the standard CLS if:\u003c\/strong\u003e You are a visual observer or use a monochrome camera with a separate IR-cut filter in your luminance (L) channel.\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 CLS-CCD and the standard CLS filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eOptolong CLS-CCD\u003c\/strong\u003e includes an integrated IR\/UV cut filter that blocks wavelengths from 300-1100nm. This is essential for color cameras (OSC\/DSLR) to prevent star bloat from infrared light. The standard CLS filter does not block IR and is intended more for visual use or monochrome imaging setups that use a separate luminance filter.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong CLS-CCD filter for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile you can, it's not ideal. The filter's transmission characteristics are optimized for the response of a digital sensor. For visual use, the standard Optolong CLS filter typically provides a brighter, more natural-looking view through the eyepiece.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Optolong CLS-CCD filter work with my unmodified DSLR camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, but with limited effectiveness for certain objects. An unmodified DSLR has its own internal filter that blocks most of the deep red H-alpha light (656nm). The CLS-CCD will still improve contrast by blocking skyglow, but to capture the rich red nebulosity in objects like the North America Nebula (NGC 7000), a \"modified\" DSLR with the stock filter removed is required.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the CLS-CCD filter affect imaging the Orion Nebula (M42) from a city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor an object like the Orion Nebula (M42), the CLS-CCD filter will dramatically improve your results from a light-polluted area. It will darken the sky background, significantly increasing the contrast of the glowing hydrogen and oxygen gases that make up the nebula. This allows you to capture much more of the faint, extended nebulosity without the image being washed out by city lights.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong CLS-CCD a good choice for imaging galaxies like Andromeda (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt's a trade-off. Galaxies like the Andromeda Galaxy (M31) are broadband objects, meaning they emit light across the entire visible spectrum, similar to stars. A light pollution filter like the CLS-CCD will block some of the galaxy's own light along with the skyglow. While it can help darken the background, it may also alter the galaxy's natural color balance. For galaxies, less aggressive filters or simply capturing more data from a dark site is often the preferred approach.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong CLS-CCD filter to look at the Sun?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eAbsolutely not.\u003c\/strong\u003e The Optolong CLS-CCD filter is \u003cstrong\u003eNOT\u003c\/strong\u003e a solar filter and is not designed for sun observation. Looking at the Sun with this filter, or any filter not explicitly designed for safe solar viewing, will cause immediate and permanent eye damage, including blindness. Always use a certified safe solar filter that covers the entire front aperture of your telescope.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eBroadband Light Pollution (LP) Filter with IR\/UV Cut\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\u003ctr\u003e\n\u003ctd\u003eSubstrate Material\u003c\/td\u003e\n\u003ctd\u003eOptical glass\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\u003eAverage Transmission\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;90%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e300-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLight Pollution Blocking\u003c\/td\u003e\n\u003ctd\u003e\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\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":52941923090717,"sku":"OPT-11901","price":133.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Mounted","offer_id":52941923123485,"sku":"OPT-11902","price":223.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-The-CLS-CCD-broadband-filter-is-designed-to-improve-the-visibility-of-various-deepsky-objects-1_19932723-0c05-473f-91d2-3b4f840aeed2.jpg?v=1789592410"},{"product_id":"optolong-l-pro-uhc-clip-filter-kit","title":"Optolong L-Pro + UHC Clip Filter Kit","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eTwo Optolong Clip-in Light Pollution Filters in One Kit\u003c\/li\u003e\n\u003cli\u003eL-Pro: Multi-Bandpass Suppression Across 380-750nm\u003c\/li\u003e\n\u003cli\u003eUHC: \u0026gt;99% Blocking of Mercury and Sodium Vapor Light (OD3)\u003c\/li\u003e\n\u003cli\u003eNatural Color on Galaxies, High Contrast on Emission Nebulae\u003c\/li\u003e\n\u003cli\u003eFits Inside the Camera Body, Works With Any Lens\u003c\/li\u003e\n\u003cli\u003eCanon EOS APS-C, Canon EOS Full Frame and Nikon Full Frame Versions\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-Pro + UHC Clip Filter Kit\u003c\/h2\u003e\n\u003cp\u003eThe Optolong L-Pro + UHC Clip Filter Kit pairs Optolong's two broadband light pollution filters in clip-in format for your DSLR. The L-Pro is the multi-bandpass filter for natural color across a 380-750nm spectrum; the UHC is the narrower, higher-contrast filter that blocks more than 99% of mercury and sodium vapor light. Both clip inside the camera body, so either one works with any lens you mount, and you choose the filter for the target and the sky rather than compromising on one.\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-Pro: Multi-Bandpass Suppression for Natural-Color Imaging\u003c\/h3\u003e\n\u003cp\u003eThe L-Pro selectively rejects the dominant emission lines of mercury vapor, high-pressure sodium and low-pressure sodium streetlights, plus the natural skyglow from neutral oxygen in the atmosphere, across its 380-750nm operating range. Its balanced, multi-bandpass design keeps the natural colors of broadband targets such as galaxies, reflection nebulae and globular clusters, so images need far less color correction. It still passes the key nebula lines, including H-Alpha, OIII, SII and H-Beta, and it blocks infrared on its own.\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\u003eUHC: Ultra High Contrast for Emission Nebulae Under City Skies\u003c\/h3\u003e\n\u003cp\u003eThe UHC takes the more aggressive approach. At an optical density of OD3 it blocks more than 99% of light from mercury vapor and sodium vapor lamps, while transmitting the emission lines of nebulae at OIII (496nm, 500nm), H-Beta (486nm) and H-Alpha (656nm). Its narrower passband gives higher contrast than a CLS filter, which makes it the better choice where light pollution is severe. Its substantial red passband captures H-Alpha well on unmodified DSLRs, for targets like the Orion Nebula (M42).\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\u003eChoosing Between the L-Pro and the UHC on a Given Night\u003c\/h3\u003e\n\u003cp\u003eThe two filters cover different targets, which is why they are worth having together:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse the L-Pro\u003c\/strong\u003e for galaxies, reflection nebulae, star clusters and Milky Way landscapes, or whenever natural star color matters. It is the more versatile filter from suburban skies.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse the UHC\u003c\/strong\u003e for emission nebulae from heavily light-polluted urban skies, where maximum contrast is the goal. It dims broadband targets such as galaxies, so switch back to the L-Pro for those.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eClip-in Format: Filtration Inside the Camera, Any Lens in Front\u003c\/h3\u003e\n\u003cp\u003eEach clip filter sits inside the camera body, so the light pollution filter works with whatever lens or telescope adapter you attach. The kit comes in three versions, each fitting one camera family:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCanon EOS APS-C:\u003c\/strong\u003e including the EOS 7D, 10D, 20D, 30D, 40D, 50D, 60D\/60Da, 70D, 550D, 600D, 650D, 700D, 1100D and 1200D.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCanon EOS Full Frame:\u003c\/strong\u003e Canon EOS full-frame DSLR bodies.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNikon Full Frame:\u003c\/strong\u003e D600, D610, D700, D750, D800, D800E, D810, D810A and Df.\u003c\/li\u003e\n\u003c\/ul\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 Quality and Durable Coatings\u003c\/h3\u003e\n\u003cp\u003eBoth filters are polished to a 60\/40 surface quality per MIL-O-13830, and the UHC to a transmitted wavefront of ¼ λ with 30s parallelism, so neither softens your images. Ion-assisted deposition coatings resist scratching and keep the central wavelength stable as the temperature changes through the night. Light pollution filters increase the contrast between the target and the sky; they do not make the object itself brighter.\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 difference between the L-Pro and the UHC in this kit?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eL-Pro\u003c\/strong\u003e is a multi-bandpass filter that blocks the main streetlight wavelengths while preserving natural color, which suits galaxies, reflection nebulae and star clusters. The \u003cstrong\u003eUHC\u003c\/strong\u003e has a narrower passband and blocks more than 99% of mercury and sodium vapor light, giving higher contrast on emission nebulae from heavily light-polluted skies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhich version of the Optolong clip filter kit fits my camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eChoose the version for your camera family: \u003cstrong\u003eCanon EOS APS-C\u003c\/strong\u003e (for example the EOS 7D, 60D\/60Da, 70D, 600D, 700D), \u003cstrong\u003eCanon EOS Full Frame\u003c\/strong\u003e, or \u003cstrong\u003eNikon Full Frame\u003c\/strong\u003e (D600, D610, D700, D750, D800, D800E, D810, D810A, Df). Both filters in a kit are the same clip format.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use these clip filters with an unmodified DSLR?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The UHC is suited to color cameras and \u003cstrong\u003eunmodified DSLRs\u003c\/strong\u003e, and its substantial red passband captures H-Alpha well. The L-Pro works for both visual observation and astrophotography and preserves natural color with any color camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhich filter should I use to photograph the Andromeda Galaxy (M31) from the suburbs?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eUse the \u003cstrong\u003eL-Pro\u003c\/strong\u003e. It darkens the suburban sky while preserving the galaxy's natural colors. The UHC blocks much of the broadband light a galaxy emits, so it would dim M31 rather than improve it.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhich filter should I use for the Orion Nebula (M42) from a city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eUse the \u003cstrong\u003eUHC\u003c\/strong\u003e. It blocks the city skyglow while passing the nebula's H-Alpha, H-Beta and OIII light, bringing out faint outer structure. The L-Pro also works on M42 and keeps more natural star colors in the surrounding field, with less contrast from severely light-polluted skies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use these filters to look at the Sun?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eNo. Never use these filters for solar observation.\u003c\/strong\u003e They are not designed for the Sun and do not block its intense radiation. Looking at the Sun through them will cause permanent blindness.\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\u003eKit Contents\u003c\/td\u003e\n\u003ctd\u003eOptolong L-Pro clip filter, Optolong UHC clip filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eL-Pro Spectrum\u003c\/td\u003e\n\u003ctd\u003e380-750nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eL-Pro Filter Type\u003c\/td\u003e\n\u003ctd\u003eMulti-bandpass light pollution filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUHC Blocking Range\u003c\/td\u003e\n\u003ctd\u003e300-700nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUHC Blocking Depth\u003c\/td\u003e\n\u003ctd\u003eOD3, light pollution line blocking \u0026gt;99%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUHC Transmitted Wavefront RMS\u003c\/td\u003e\n\u003ctd\u003e¼ λ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUHC Parallelism\u003c\/td\u003e\n\u003ctd\u003e30s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40 (MIL-O-13830)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoating Technology\u003c\/td\u003e\n\u003ctd\u003eIon-assisted deposition multi-layer coatings\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable Versions\u003c\/td\u003e\n\u003ctd\u003eClip for Canon EOS APS-C, Clip for Canon EOS Full Frame, Clip for Nikon Full Frame\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-Pro Clip Filter (in selected version)\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eOptolong UHC Clip Filter (in selected version)\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":"Clip for Canon EOS APS-C","offer_id":52941931872541,"sku":"OPT-LPRO-UHC-EOS-APSC","price":419.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Canon EOS Full Frame","offer_id":52941931905309,"sku":"OPT-LPRO-UHC-EOS-FF","price":419.0,"currency_code":"CAD","in_stock":true},{"title":"Clip for Nikon Full Frame","offer_id":52941931938077,"sku":"OPT-LPRO-UHC-NIKON-FF","price":419.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-UHC-L-Pro-Kit.webp?v=1789606223"}],"url":"https:\/\/davidastro.com\/en-us\/collections\/optolong-light-pollution-filters.oembed","provider":"David Astro","version":"1.0","type":"link"}