{"product_id":"optolong-moon-skyglow-filter","title":"Optolong Moon \u0026 Skyglow Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eBlocks over 99% of common light pollution emission lines\u003c\/li\u003e\n\u003cli\u003eMaintains over 90% average transmission for bright, detailed views\u003c\/li\u003e\n\u003cli\u003eλ\/4 transmitted wavefront ensures no image degradation\u003c\/li\u003e\n\u003cli\u003eDurable B270 substrate with 1.85mm thickness\u003c\/li\u003e\n\u003cli\u003eAvailable in 1.25\" and 2\" mounted sizes\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 Moon \u0026amp; Skyglow Filter\u003c\/h2\u003e\n\u003cp\u003eThe Optolong Moon \u0026amp; Skyglow Filter dramatically improves visual and photographic contrast by blocking over 99% of disruptive artificial light pollution and natural skyglow. By maintaining an average transmission greater than 90% for desirable wavelengths, it darkens the sky background without dimming celestial targets, all while preserving image sharpness with a λ\/4 transmitted wavefront across its 1.85mm thick B270 glass substrate.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e\u0026gt;99% Light Pollution Rejection with \u0026gt;90% Transmission\u003c\/h3\u003e\n\u003cp\u003eThis filter isolates and rejects the most common sources of light pollution, such as sodium vapor streetlights, darkening the sky background to make faint details visible. With a high transmission rate of over 90% across the visible spectrum, galaxies, nebulae, and star clusters retain their brightness and structure, resulting in a significantly higher-contrast view.\u003c\/p\u003e\n\u003cp\u003eThis balanced approach makes the Moon \u0026amp; Skyglow filter highly versatile. It provides a noticeable improvement from moderately light-polluted skies without the aggressive color shifting of narrowband filters, making it an ideal general-purpose tool for both visual observing and astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eλ\/4 Wavefront Accuracy and Durable B270 Construction\u003c\/h3\u003e\n\u003cp\u003eAn astronomical filter is useless if it degrades the sharp image from your telescope. Optolong constructs the Moon \u0026amp; Skyglow filter from B270 optical glass polished to a λ\/4 transmitted wavefront accuracy and 30s parallelism. These specifications ensure that the filter will not introduce aberrations or distortions, preserving the fine details on planetary surfaces and the pinpoint sharpness of stars.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIon-Assisted Coatings:\u003c\/strong\u003e Precision coatings are applied using an ion-assisted deposition process, ensuring durability, scratch resistance, and stable performance that does not shift with temperature changes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e60\/40 Surface Quality:\u003c\/strong\u003e This specification controls for cosmetic imperfections, guaranteeing a clean optical surface that won't scatter light or reduce contrast.\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 primary purpose of the Optolong Moon \u0026amp; Skyglow filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Optolong Moon \u0026amp; Skyglow filter is a broadband light pollution filter designed to increase the contrast of celestial objects. It selectively blocks common wavelengths of artificial light and natural skyglow, which darkens the sky background and makes faint details on the Moon, planets, galaxies, and nebulae easier to see.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Optolong Moon \u0026amp; Skyglow filter improve my view of the Orion Nebula (M42) from the suburbs?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFrom a suburban location, the skyglow washes out the faint, outer structures of nebulae like M42. The Optolong Moon \u0026amp; Skyglow filter blocks this interfering light, making the sky background appear much darker. This allows the faint nebulosity extending from the core of the Orion Nebula to stand out, revealing more of its intricate dust lanes and structure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong Moon \u0026amp; Skyglow filter effective for planetary viewing in an 8\" SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it can be beneficial. While planets are bright, they are often observed against a bright sky background, especially at lower altitudes. The filter darkens the sky immediately surrounding the planet, which can increase the perceived contrast of subtle details like Jupiter's cloud bands or Saturn's Cassini Division. It also helps reduce glare when observing the bright lunar surface.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong Moon \u0026amp; Skyglow filter suitable for astrophotography?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, this filter is very effective for astrophotography, particularly with one-shot color cameras. By blocking over 99% of major light pollution sources, it allows for longer sub-exposures before the skyglow saturates the sensor. This results in cleaner images with better contrast and more natural star colors compared to unfiltered shots from a light-polluted area.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the λ\/4 wavefront specification mean for the Optolong Moon \u0026amp; Skyglow filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA \u003cstrong\u003eλ\/4 (1\/4 wave)\u003c\/strong\u003e wavefront rating is a measure of optical precision. It guarantees that the filter's glass is flat and parallel enough that it will not distort the light passing through it by more than one-quarter of a wavelength of light. This is critical for high-resolution viewing and imaging, as it ensures the filter will not degrade the sharpness of the image produced by your telescope.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong Moon \u0026amp; Skyglow filter for solar observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eAbsolutely not.\u003c\/strong\u003e This filter is designed for night-sky use only and provides no protection from the Sun's harmful radiation. Looking at the Sun with this filter, or any filter not specifically designed for safe solar observation, will cause immediate and permanent eye damage, including blindness. Always use a certified solar filter that covers the front 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\u003eSubstrate\u003c\/td\u003e\n\u003ctd\u003eB270 Optical 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 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 RMS\u003c\/td\u003e\n\u003ctd\u003eλ\/4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e30s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable Sizes\u003c\/td\u003e\n\u003ctd\u003e1.25\" Mounted, 2\" Mounted\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eOptolong Moon \u0026amp; Skyglow 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\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":52941911294237,"sku":"OPT-10501","price":45.0,"currency_code":"CAD","in_stock":true},{"title":"2\" Mounted","offer_id":52941911327005,"sku":"OPT-10502","price":67.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-Moon-Skyglow-Filter-1_176bee0d-3759-4793-929e-bc873bad8163.jpg?v=1789592332","url":"https:\/\/davidastro.com\/products\/optolong-moon-skyglow-filter","provider":"David Astro","version":"1.0","type":"link"}