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