{"product_id":"optolong-h-alpha-7nm-narrowband-filter","title":"Optolong H-Alpha 7nm Narrowband Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eIsolates the 656nm Hydrogen-alpha emission line\u003c\/li\u003e\n\u003cli\u003e7nm bandpass for maximum contrast\u003c\/li\u003e\n\u003cli\u003eBlocks mercury vapor, sodium vapor, and natural skyglow\u003c\/li\u003e\n\u003cli\u003eIdeal for SHO \"Hubble Palette\" and LRGB+Ha imaging\u003c\/li\u003e\n\u003cli\u003eIon-assisted multi-layer coatings for durability\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\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 H-Alpha 7nm Narrowband Filter\u003c\/h2\u003e\n      \u003cp\u003eThe Optolong H-Alpha 7nm Narrowband Filter is an essential tool for deep-sky astrophotography, designed to isolate the hydrogen-alpha emission line at a 656nm wavelength. By restricting the bandwidth to just 7nm, this filter dramatically increases the contrast between emission nebulae and the background sky. It achieves this by aggressively blocking common sources of light pollution, including mercury and sodium vapor lights, as well as the natural skyglow caused by atmospheric oxygen emission.\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\u003e7nm Bandpass at 656nm: The Key to High-Contrast Nebula Imaging\u003c\/h3\u003e\n      \u003cp\u003eThe core of this filter's design is its extremely narrow 7nm bandpass centered on the 656nm H-alpha line. This precision allows you to capture the faint, intricate structures within emission nebulae like the Rosette Nebula (Caldwell 49) or the Pillars of Creation in the Eagle Nebula (M16), even under the glare of a full moon or from a light-polluted suburban backyard. The filter doesn't make the nebula brighter; it darkens the sky background so severely that the nebula's signal stands out in sharp relief, revealing details that would otherwise be completely 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\u003eSHO \u0026amp; LRGB+Ha: Unlocking 2 Advanced Astrophotography Workflows\u003c\/h3\u003e\n      \u003cp\u003eThe H-Alpha 7nm filter is a cornerstone for two primary advanced imaging techniques. For monochrome camera users, it serves as the \"S\" (Sulfur-II), \"H\" (Hydrogen-alpha), and \"O\" (Oxygen-III) foundation for creating stunning \"Hubble Palette\" images. This technique allows you to continue imaging productively even when the moon is out, turning potential downtime into valuable data collection.\u003c\/p\u003e\n      \u003cp\u003eIt's also the first and most critical narrowband addition for imagers using a standard LRGB filter set. By capturing a separate H-alpha channel and blending it with your RGB data, you can dramatically enhance the structural detail and contrast of red nebulae while maintaining a natural star field color, adding a professional touch to your final images.\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: Ensuring 0 CWL Deviation From Temperature Shifts\u003c\/h3\u003e\n      \u003cp\u003eOptolong utilizes an advanced ion-assisted deposition coating process to ensure the filter is both durable and optically stable. This technology produces a hard, scratch-resistant surface that stands up to regular cleaning and handling in the field. Critically, it also ensures the central wavelength (CWL) does not deviate with temperature changes during an imaging session, preventing your signal from drifting out of the narrow 7nm bandpass and maintaining consistent results from dusk till dawn.\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\"\u003eWhat is the main purpose of the Optolong H-Alpha 7nm filter?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe Optolong H-Alpha 7nm filter is designed for deep-sky astrophotography with monochrome or color cameras. Its primary function is to isolate the \u003cstrong\u003e656nm hydrogen-alpha wavelength\u003c\/strong\u003e with a very narrow \u003cstrong\u003e7nm bandpass\u003c\/strong\u003e. This dramatically increases contrast by blocking light pollution and natural skyglow, making it possible to capture faint emission nebulae.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Optolong H-Alpha 7nm filter for visual observing?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThis filter is not recommended for visual use. Narrowband filters like this one have extremely low light transmission outside their specified bandpass, making the view through an eyepiece incredibly dim. They are designed for long-exposure astrophotography, where a camera sensor can accumulate light over many minutes or hours.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Optolong 7nm H-Alpha filter help in light-polluted skies?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eLight pollution from city lights is primarily composed of specific wavelengths, such as those from \u003cstrong\u003emercury vapor\u003c\/strong\u003e and \u003cstrong\u003esodium vapor\u003c\/strong\u003e lamps. The Optolong H-Alpha 7nm filter is engineered to block these wavelengths completely, along with unwanted natural skyglow. By only allowing the 656nm light from the nebula to pass through, it creates a near-black sky background, making the nebula's signal stand out dramatically.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow would I use the Optolong H-Alpha 7nm filter to image the Rosette Nebula (Caldwell 49) from my backyard?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eTo image the Rosette Nebula with the Optolong H-Alpha 7nm filter, you would place it in your filter wheel or drawer in front of your monochrome camera. Because the filter is so restrictive, you will need to take long exposures, typically 5 to 20 minutes each, depending on your telescope's focal ratio. You would then stack many of these sub-exposures to create a final, high-contrast black-and-white image revealing the nebula's intricate hydrogen structures.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eI have an LRGB filter set and a monochrome camera. How do I incorporate the Optolong H-Alpha 7nm filter into my workflow?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe Optolong H-Alpha 7nm filter is the perfect first step into advanced LRGB imaging. You would capture your standard Luminance, Red, Green, and Blue data as usual. Then, you capture a separate set of exposures using the H-Alpha filter. In post-processing, you can blend this detailed H-alpha data into your red channel or use it as a separate luminance layer to significantly enhance the detail and \"pop\" of any emission regions within your target.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the \"SHO\" or \"Hubble Palette\" and how does the Optolong H-Alpha 7nm filter fit in?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe \"SHO\" or \"Hubble Palette\" is a popular narrowband imaging technique that assigns data from three different filters to the RGB channels of a color image. The Optolong H-Alpha 7nm filter provides the \"H\" data. Typically:\u003c\/p\u003e\n    \u003cul\u003e\n      \u003cli\u003e\n\u003cstrong\u003eSulfur-II (SII) data\u003c\/strong\u003e is mapped to the Red channel.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eHydrogen-alpha (H-alpha) data\u003c\/strong\u003e is mapped to the Green channel.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eOxygen-III (OIII) data\u003c\/strong\u003e is mapped to the Blue channel.\u003c\/li\u003e\n    \u003c\/ul\u003e\n    \u003cp\u003eThis creates false-color images with high scientific value and striking aesthetic appeal, famously used for images like the \"Pillars of Creation\" (M16).\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\u003eBandpass\u003c\/td\u003e\n\u003ctd\u003e7nm\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eCentral Wavelength\u003c\/td\u003e\n\u003ctd\u003e656nm (Hydrogen-alpha)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eAvailable Formats\u003c\/td\u003e\n\u003ctd\u003e1.25\" Mounted, 2\" Mounted, 36mm Round Unmounted\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/li\u003e\n\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 H-Alpha 7nm 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":52941912965405,"sku":"OPT-11301","price":159.0,"currency_code":"USD","in_stock":true},{"title":"2\" Mounted","offer_id":52941912998173,"sku":"OPT-11302","price":229.0,"currency_code":"USD","in_stock":true},{"title":"36mm Round Unmounted","offer_id":52941913030941,"sku":"OPT-11307","price":189.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-H-Alpha-7nm-Narrowband-Filter-Improved-Version-for-deepsky-nebula-imaging-1_75eadee5-ff2e-45d6-8d76-899d79b53119.jpg?v=1789592351","url":"https:\/\/davidastro.com\/en-us\/products\/optolong-h-alpha-7nm-narrowband-filter","provider":"David Astro","version":"1.0","type":"link"}