{"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","url":"https:\/\/davidastro.com\/products\/optolong-cls-ccd-filter","provider":"David Astro","version":"1.0","type":"link"}