{"product_id":"explore-scientific-310130","title":"Explore Scientific Nebula Filter H-Alpha 2-inch 12nm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eIsolates the Hydrogen-alpha emission line at a 12nm bandpass\u003c\/li\u003e\n\u003cli\u003eStandard 2-inch filter format for modern focusers and filter wheels\u003c\/li\u003e\n\u003cli\u003eDramatically increases nebula contrast under light-polluted skies\u003c\/li\u003e\n\u003cli\u003eEngineered for deep-sky astrophotography\u003c\/li\u003e\n\u003cli\u003eIncludes an individual test report to guarantee performance\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\u003eNebula Filter H-Alpha 2-inch 12nm\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific Nebula Filter isolates the critical Hydrogen-alpha emission line with a 12nm bandpass, specifically designed for 2-inch format imaging trains. This 12nm passband dramatically increases contrast on emission nebulae by rejecting broadband light pollution from city skies, making it an essential tool for urban astrophotography in any 2-inch focuser or filter wheel.\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 12nm H-Alpha Bandpass: Isolating Emission Nebulae\u003c\/h3\u003e\n\u003cp\u003eEmission nebulae, like the North American Nebula (NGC 7000) or the Heart Nebula (IC 1805), radiate strongly in the red light of ionized hydrogen. The Explore Scientific H-Alpha filter features a narrow 12nm window centered on this wavelength, allowing the faint, detailed structures of the nebula to pass through to your camera sensor while blocking nearly all other light.\u003c\/p\u003e\n\u003cp\u003eThis targeted transmission is the key to defeating light pollution. By rejecting the broad-spectrum glow from mercury and sodium-vapor streetlights, the filter renders the sky background black, causing the nebula's signal to stand out with stark contrast. Faint tendrils and wisps of gas that are completely invisible without a filter suddenly become photographable, even from a suburban backyard.\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: Guaranteed 12nm Performance\u003c\/h3\u003e\n\u003cp\u003eA narrowband filter's effectiveness depends entirely on the accuracy of its bandpass. Explore Scientific ensures this by including an individual test report with every H-alpha filter, verifying its specific transmission characteristics. This isn't just a generic specification sheet; it's a certificate of performance for the exact filter you receive.\u003c\/p\u003e\n\u003cp\u003eThis commitment to quality control guarantees that the filter meets its stated 12nm specification, ensuring you get the light pollution rejection and nebula-enhancing results you expect. It provides the confidence that your equipment is performing optimally for capturing the highest quality astrophotos.\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\u003eChoosing a 12nm Filter: When Wider is Better\u003c\/h3\u003e\n\u003cp\u003eWhile filters with narrower bandpasses, such as 7nm or 3nm, can offer more extreme contrast under the most severe light pollution, they come with trade-offs. The Explore Scientific 12nm H-Alpha filter strikes a critical balance between contrast and signal strength, making it a highly practical choice for many imagers.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eShorter Exposures:\u003c\/strong\u003e The 12nm window gathers more photons than narrower designs, allowing you to achieve a strong signal with shorter sub-exposure times. This reduces demands on your mount's tracking accuracy.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLess Susceptible to Band-Shift:\u003c\/strong\u003e Very fast optical systems (f\/4 or below) can cause wavelength shifts in narrowband filters. The wider 12nm bandpass is more forgiving of this effect, ensuring consistent performance across a broader range of telescopes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStronger Star Signal:\u003c\/strong\u003e The 12nm bandpass allows for slightly brighter, more natural-looking stars in the final image compared to the pinpricks rendered by ultra-narrowband filters.\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 main advantage of the Explore Scientific 12nm H-Alpha filter for urban astrophotography?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary advantage is its ability to dramatically increase the contrast between emission nebulae and a light-polluted sky. By blocking the wavelengths associated with common streetlights and passing only the \u003cstrong\u003e12nm window\u003c\/strong\u003e around the H-alpha line, the filter makes it possible to capture detailed deep-sky images from city and suburban locations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 12nm bandpass on this H-Alpha filter affect my exposure times compared to a 7nm filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA 12nm filter allows more light to reach the sensor than a narrower 7nm filter. This means you can typically use \u003cstrong\u003eshorter sub-exposure times\u003c\/strong\u003e to achieve the same signal level. While a 7nm filter may provide higher contrast, the 12nm filter is more efficient and less demanding on your mount's tracking.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Explore Scientific 2-inch H-Alpha filter for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this filter is designed exclusively for \u003cstrong\u003eastrophotography\u003c\/strong\u003e. The 12nm bandpass is so restrictive that it blocks almost all visible light, and the view through an eyepiece would be extremely dim or completely black. Your eye is not sensitive enough to perceive the faint nebula light it passes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will this 12nm H-Alpha filter perform on the Orion Nebula (M42) from a Bortle 7 zone?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFrom a Bortle 7 zone, this filter would be highly effective on the Orion Nebula (M42). It will suppress the bright urban skyglow, allowing you to capture the intricate, filamentary details in the nebula's outer wings that are normally washed out. It will also help control the brightness of the Trapezium star cluster, preventing it from completely blowing out the core of the nebula in your images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Explore Scientific 12nm H-Alpha filter a good choice for imaging with a fast f\/4 Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it's an excellent choice. Fast optical systems can cause a phenomenon called \"band-shift\" with very narrow filters. The wider \u003cstrong\u003e12nm bandpass\u003c\/strong\u003e of the Explore Scientific filter is more tolerant of this effect, ensuring that the H-alpha emission line is not shifted out of the filter's passband. This makes it a reliable and efficient option for fast reflectors and astrographs.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the individual test report for the Explore Scientific H-Alpha filter tell me?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe individual test report is a certificate of quality assurance. It provides a graph showing the exact transmission curve for your specific filter, confirming its \u003cstrong\u003ecentral wavelength (CWL) and full width at half maximum (FWHM)\u003c\/strong\u003e. This guarantees that your filter performs to the advertised 12nm specification.\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 Type\u003c\/td\u003e\n\u003ctd\u003eH-Alpha Narrowband\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e2-inch\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\u003c\/tbody\u003e\n\u003c\/table\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\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":52909403537693,"sku":"ES-310130","price":249.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ExploreScientific-Nebula-Filter-H-Alpha-2-inch-12nm-1_ba9a2f7a-f5d9-401c-8b89-650bf70acd4d.jpg?v=1789061595","url":"https:\/\/davidastro.com\/en-us\/products\/explore-scientific-310130","provider":"David Astro","version":"1.0","type":"link"}