{"product_id":"explore-scientific-310135","title":"Explore Scientific Nebula Filter H-Alpha 1.25-inch 12nm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eTargets Hydrogen-Alpha emission nebulae\u003c\/li\u003e\n\u003cli\u003e12nm bandpass for astrophotography\u003c\/li\u003e\n\u003cli\u003e1.25-inch standard filter size\u003c\/li\u003e\n\u003cli\u003eDrastically improves contrast under light-polluted skies\u003c\/li\u003e\n\u003cli\u003eIncludes an individual factory test report\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\u003eDownloads\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\u003eExplore Scientific Nebula Filter H-Alpha 1.25-inch 12nm\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific H-Alpha Nebula Filter isolates a specific 12nm bandpass of deep-red light, making it possible to capture hydrogen-rich emission nebulae from light-polluted skies with any 1.25-inch compatible camera. This 12nm width is designed specifically for astrophotography, effectively blocking interfering city light to reveal faint structures that would otherwise be completely washed out by skyglow.\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\u003eIsolate the Signal: Targeting Hydrogen-Alpha with a 12nm Bandpass\u003c\/h3\u003e\n\u003cp\u003eEmission nebulae, like the Orion Nebula (M42) and the North American Nebula (NGC 7000), glow intensely in the specific wavelength of light emitted by energized hydrogen atoms. This filter is engineered to block nearly all light except for a narrow 12nm window centered on this hydrogen-alpha line, causing the nebula's signal to stand out dramatically against a darkened background.\u003c\/p\u003e\n\u003cp\u003eThe 12nm bandpass offers a practical balance for many imagers. It is wide enough to allow for shorter exposure times than ultra-narrowband filters, making it more forgiving in average seeing conditions and a good match for a wider range of telescopes, including those with slower focal ratios.\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\u003eUrban Astrophotography: A 12nm Solution to City Glow\u003c\/h3\u003e\n\u003cp\u003eLight pollution is the single greatest challenge for deep-sky imaging from populated areas. This H-Alpha filter acts as a direct countermeasure, aggressively rejecting the broad-spectrum glare from mercury-vapor and sodium-vapor streetlights that dominate the urban night sky. The effect is transformative, turning a washed-out, empty-looking frame into one filled with detailed nebulosity.\u003c\/p\u003e\n\u003cp\u003eFor astrophotographers working from a backyard in the city or suburbs, the Explore Scientific 12nm H-Alpha filter makes it possible to capture high-contrast images that were previously only achievable from remote dark-sky sites. It is an essential tool for revealing the full extent of faint emission nebulae despite challenging local conditions.\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\u003eIndividually Tested for Transmission Confidence\u003c\/h3\u003e\n\u003cp\u003eNot all filters are created equal. To ensure you receive a high-quality filter that performs as advertised, Explore Scientific includes an individual test report with every H-Alpha filter. This certificate verifies the filter's specific transmission curve, giving you confidence that its bandpass and blocking capabilities meet stringent quality control standards.\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\"\u003eWhat is the main purpose of the Explore Scientific 12nm H-Alpha filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis filter is designed exclusively for \u003cstrong\u003eastrophotography of emission nebulae\u003c\/strong\u003e. It isolates the hydrogen-alpha wavelength of light, which dramatically increases contrast and reveals faint details, especially when imaging from light-polluted areas.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the 1.25-inch H-Alpha 12nm filter for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this filter is not recommended for visual use. The 12nm bandpass is very restrictive and passes only a thin slice of deep red light, making the view through an eyepiece extremely dim. It is designed to be used with a camera sensor, which can accumulate light over long exposures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy would I choose the 12nm H-Alpha filter over a narrower one?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA 12nm bandpass is a versatile choice that balances contrast enhancement with light-gathering ability. Compared to tighter 7nm or 5nm filters, the 12nm filter allows for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eShorter exposure times,\u003c\/strong\u003e which can be beneficial in average seeing conditions or for capturing more frames in a session.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBetter compatibility\u003c\/strong\u003e with slower focal ratio telescopes (f\/8 and above), which may struggle to gather enough signal with ultra-narrow filters.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Explore Scientific 12nm H-Alpha filter improve my images of the Rosette Nebula (NGC 2244) from a city?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Rosette Nebula is rich in hydrogen-alpha emissions but is often faint and washed out from city skies. By using the Explore Scientific 12nm H-Alpha filter, you will block the interfering city glow, darkening the sky background in your images. This allows the faint, red nebulosity of the Rosette to be captured with far greater contrast and detail than would be possible without the filter.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI have an 8-inch f\/10 SCT. Is the 12nm H-Alpha filter a good choice for it?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the 12nm bandpass is an excellent choice for an f\/10 Schmidt-Cassegrain Telescope. Slower optical systems like SCTs benefit from the slightly wider bandpass, which gathers more photons and allows you to achieve a strong signal with reasonable exposure times. An ultra-narrow filter (like 3nm) might require prohibitively long exposures with an f\/10 system.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is an individual test report included with the Explore Scientific H-Alpha filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe included test report is your assurance of quality. It provides a specific measurement of your filter's performance, confirming that its central wavelength and 12nm bandpass are accurately manufactured. This ensures you get the high-contrast results and effective light pollution suppression you expect.\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 Size\u003c\/td\u003e\n\u003ctd\u003e1.25-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eH-Alpha Nebula Filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandpass\u003c\/td\u003e\n\u003ctd\u003e12nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Use\u003c\/td\u003e\n\u003ctd\u003eAstrophotography\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\"\u003eNebula Filter H-Alpha 1.25-inch 12nm\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\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":52909387841821,"sku":"ES-310135","price":224.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ExploreScientific-Nebula-Filter-H-Alpha-1-25-inch-12nm-1_82076b6b-fcf7-42b1-95d1-e075e0d2cc17.jpg?v=1789061556","url":"https:\/\/davidastro.com\/fr\/products\/explore-scientific-310135","provider":"David Astro","version":"1.0","type":"link"}