{"title":"Filtres antipollution lumineuse Optolong CLS","description":"\u003cp\u003eLes filtres antipollution lumineuse Optolong CLS sont des filtres à large bande qui coupent la lumière des éclairages publics courants tout en laissant passer l'essentiel de l'émission des nébuleuses. La gamme compte deux versions : le CLS, pour les appareils reflex et hybrides qui conservent leur filtre IR interne, et le CLS-CCD, qui ajoute un blocage infrarouge pour les caméras astronomiques qui n'en ont pas.\u003c\/p\u003e\u003cp\u003eC'est un premier filtre simple pour l'imagerie couleur ou le visuel en banlieue.\u003c\/p\u003e","products":[{"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"}],"url":"https:\/\/davidastro.com\/fr\/collections\/optolong-cls-light-pollution-filters.oembed","provider":"David Astro","version":"1.0","type":"link"}