{"product_id":"optolong-lrgb-h-alpha-7nm-filter-set-5-pcs","title":"Optolong LRGB + H-Alpha 7nm Filter Set","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eComplete 5-Filter LRGB and H-Alpha Set\u003c\/li\u003e\n\u003cli\u003e7nm H-Alpha Filter Centered at 656.3nm\u003c\/li\u003e\n\u003cli\u003eBlocks 589nm Sodium Light Pollution Line\u003c\/li\u003e\n\u003cli\u003eHigh Transmission for Natural Color Balance\u003c\/li\u003e\n\u003cli\u003eAvailable in 1.25\", 2\", and 36mm Unmounted 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 LRGB + H-Alpha 7nm Filter Set\u003c\/h2\u003e\n\u003cp\u003eThis 5-filter Optolong LRGB + H-Alpha 7nm Filter Set provides a complete solution for monochrome deep-sky imaging, combining four high-contrast broadband filters with a narrow 7nm Hydrogen-Alpha filter centered at 656.3nm. The LRGB filters are engineered with a spectral gap to block the primary sodium light pollution line at 589nm, ensuring superior color separation on galaxies and star clusters. The included 7nm H-Alpha filter isolates critical emission nebula structures, providing the essential data needed to create deeply detailed composite images from any location.\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 4-Filter LRGB System for Broadband Color\u003c\/h3\u003e\n\u003cp\u003eThe core of this set is the Luminance, Red, Green, and Blue filter quartet, designed for maximum contrast and sharp color differentiation. The OIII emission lines are passed through both the blue and green filters, allowing for high-efficiency capture of planetary nebulae and supernova remnants with natural, balanced color. Extremely high gradients between the passbands ensure that data from each channel is cleanly separated for easier processing.\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\u003eSuppressing City Glow: The 589nm Sodium Line Block\u003c\/h3\u003e\n\u003cp\u003eA key feature of the Optolong LRGB design is the deliberate gap between the green and red filters' transmission windows. This gap is precisely engineered to block the prominent sodium light pollution line at 589nm. By rejecting this common source of urban skyglow, the filters significantly improve color balance and saturation, allowing you to capture cleaner raw data even from 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\u003eThe 7nm, 656.3nm H-Alpha Filter: Isolating Emission Nebulae\u003c\/h3\u003e\n\u003cp\u003eThe fifth filter in the set is a 7nm narrowband H-Alpha filter centered on the 656.3nm wavelength. This filter isolates the most common emission signal in the universe, dramatically increasing the contrast of hydrogen-rich targets like the Orion Nebula (M42) or the North American Nebula (NGC 7000). It aggressively suppresses starlight and background light pollution, revealing faint, intricate nebulosity that is invisible to broadband filters.\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\u003eLRGB+Ha vs. LRGB-Only: A 5-Filter Imaging Workflow\u003c\/h3\u003e\n\u003cp\u003eWhile an LRGB set is sufficient for broadband targets like galaxies and star clusters, the addition of the H-Alpha filter unlocks a new level of detail and creativity. For emission nebulae, you can substitute the Red channel data with the H-Alpha data for a dramatic \"HaRGB\" composite. For galaxies with active star-forming regions, like the Triangulum Galaxy (M33), you can blend the H-Alpha data into the Luminance or Red channels to make the HII regions pop against the stellar background, a technique not possible with a 4-filter set alone.\u003c\/p\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\"\u003eHow do I use the H-Alpha filter in the Optolong LRGB+Ha set?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe H-Alpha filter can be used in several ways. You can capture it as a separate channel and blend it into your final LRGB image to enhance red nebulosity. A common technique is to substitute the data from the Red filter with your H-Alpha data to create a high-contrast HaRGB image, or to add it to the Luminance channel for a sharper, more detailed final result.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the 589nm block in this Optolong set eliminate all light pollution?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, but it is highly effective against a primary source. The gap between the green and red filters specifically targets sodium vapor lamps, which are a major component of urban skyglow. While it won't block modern LED lighting, it significantly improves color balance and contrast compared to filters without this feature, especially from older city lighting.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Optolong 7nm H-Alpha filter suitable for very fast telescopes?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, Optolong filters are designed to minimize band-shifting with faster optical systems. While all interference filters experience some degree of shift, the \u003cstrong\u003e7nm bandpass\u003c\/strong\u003e is wide enough to remain effective on most common amateur telescopes, including f\/4 and f\/5 systems, without significant signal loss.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use this Optolong filter set with a color camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis set is designed for \u003cstrong\u003emonochrome cameras\u003c\/strong\u003e. A monochrome sensor allows you to capture data through each filter separately (L, R, G, B, Ha) and combine them during processing for a full-color image. A color camera already has a red, green, and blue filter array built into its sensor, making these filters redundant and ineffective.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eFor a target like the Andromeda Galaxy (M31), is the H-Alpha filter from the Optolong set useful?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. While the Andromeda Galaxy is primarily a broadband target, its spiral arms contain numerous star-forming HII regions that glow in H-Alpha light. Capturing data with the \u003cstrong\u003e7nm H-Alpha filter\u003c\/strong\u003e and blending it into your LRGB data will make these pink and red knots of nebulosity stand out dramatically, adding depth and scientific detail to your final image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow should I approach imaging the Pelican Nebula (IC 5070) with this Optolong LRGB+Ha set?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Pelican Nebula is an emission nebula rich in Hydrogen-Alpha. For this target, you should dedicate most of your imaging time to the \u003cstrong\u003e7nm H-Alpha filter\u003c\/strong\u003e to capture the faint structures and contrast. Use the L, R, G, and B filters primarily to capture star colors, then combine all five channels in processing. You can use the H-Alpha data as a detailed layer for your red channel or as a synthetic luminance.\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\u003eSet Contents\u003c\/td\u003e\n\u003ctd\u003e5 Filters: Luminance, Red, Green, Blue, H-Alpha\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eH-Alpha Bandwidth\u003c\/td\u003e\n\u003ctd\u003e7nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eH-Alpha Center Wavelength\u003c\/td\u003e\n\u003ctd\u003e656.3nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLight Pollution Rejection\u003c\/td\u003e\n\u003ctd\u003eBlocks 589nm Sodium Line\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable Sizes\u003c\/td\u003e\n\u003ctd\u003e1.25\" Mounted, 2\" Mounted, 36mm Unmounted\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\"\u003eLuminance (L) 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\"\u003eRed (R) 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\"\u003eGreen (G) 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\"\u003eBlue (B) 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\"\u003eH-Alpha (Ha) 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\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":52941929513245,"sku":"OPT-LRGBH-1.25","price":369.0,"currency_code":"USD","in_stock":true},{"title":"2\" Mounted","offer_id":52941929546013,"sku":"OPT-LRGBH-2","price":569.0,"currency_code":"USD","in_stock":true},{"title":"36mm Round Unmounted","offer_id":52941929578781,"sku":"OPT-LRGBH-RD36","price":439.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Optolong-HaLRGB-Filter-Kit.webp?v=1789606275","url":"https:\/\/davidastro.com\/en-us\/products\/optolong-lrgb-h-alpha-7nm-filter-set-5-pcs","provider":"David Astro","version":"1.0","type":"link"}