{"product_id":"antlia-3nm-narrowband-h-beta-pro-filter","title":"Antlia 3nm Narrowband H-Beta Pro Filter - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eIsolates the H-Beta emission line at 486.1nm\u003c\/li\u003e\n\u003cli\u003eUltra-narrow 3nm bandpass for maximum contrast\u003c\/li\u003e\n\u003cli\u003eHigh 88% peak transmission for strong signal\u003c\/li\u003e\n\u003cli\u003eUsable down to f\/3 with minimal loss of signal\u003c\/li\u003e\n\u003cli\u003e2\" mounted format with M48x0.75 threads\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\u003eAntlia 3nm Narrowband H-Beta Pro Filter - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Antlia 3nm Narrowband H-Beta Pro filter isolates the hydrogen-beta emission line at a central wavelength of 486.1nm with an extremely tight 3nm full width at half maximum (FWHM). This narrow bandpass achieves a peak transmission of 88% while delivering greater than OD5 out-of-band blocking from 300-1100nm. Built on a single, non-glued optical substrate with a transmitted wavefront of Lambda\/4 or better, the filter can be used down to f\/3 with minimal loss of signal, in light-polluted areas and at dark sites.\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\u003e3nm Bandpass at 486.1nm: Isolate H-Beta with 88% Transmission\u003c\/h3\u003e\n\u003cp\u003eBy restricting the incoming light to a 3nm window centered on 486.1nm, the Antlia H-Beta Pro enhances the contrast of emission targets by reducing unwanted background signals. With 88% transmission at the 486.1nm line, it provides strong signal and well-defined nebula structures on H-Beta emission nebulae such as the California Nebula (NGC 1499). Antlia notes the filter is only effective for deep-sky objects that contain H-Beta emissions.\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\u003eOD5 Blocking and Lambda\/4 Optics: Suppressing Halos and Noise\u003c\/h3\u003e\n\u003cp\u003eThe filter's construction is critical for clean data. Its greater than OD5 blocking, which attenuates unwanted wavelengths by a factor of 100,000, ensures an excellent signal-to-noise ratio and minimizes interference from other wavelengths. A single substrate eliminates internal reflections, the transmitted wavefront is Lambda\/4 or better with parallelism of less than 30 arcseconds, and the steep spectral profile minimizes halos around bright stars.\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\u003eUsable Down to f\/3: Built for Fast Optics\u003c\/h3\u003e\n\u003cp\u003eA key challenge with narrowband filters is band-shifting in fast optical systems. The Antlia 3nm Pro series is specifically designed to be used down to f\/3 with minimal signal loss. This makes it a practical choice for fast imaging systems down to that focal ratio.\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\u003eAntlia 3nm Pro vs. Wider H-Beta Filters: A Contrast Trade-Off\u003c\/h3\u003e\n\u003cp\u003eCompared to filters with a 7nm or wider bandpass, the Antlia 3nm Pro offers a significant advantage in contrast, particularly from urban or suburban locations. The trade-off for this enhanced contrast is a need for longer exposure times to achieve the same signal level. \u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAntlia 3nm Pro:\u003c\/strong\u003e Delivers higher contrast by rejecting more background light. Antlia notes it can be used in light-polluted areas and dark sites, and extends imaging time when the moon is up.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWider 7nm+ Filters:\u003c\/strong\u003e Capture more signal in a shorter time frame and are more forgiving of slight band-shifting on very fast systems (below f\/4). However, they allow more background signal through, reducing overall 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\"\u003eWhy would I choose the Antlia 3nm H-Beta Pro filter over an H-Alpha or OIII filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Antlia 3nm H-Beta Pro is a specialized filter for objects that have strong hydrogen-beta emissions but may be weaker in other wavelengths. Antlia notes it is only effective for deep-sky objects that contain H-Beta emissions, such as the \u003cstrong\u003eCalifornia Nebula (NGC 1499)\u003c\/strong\u003e. As part of the 3nm Pro series alongside Ha, SII, OIII and NII, it adds another channel for combining narrowband data in post-processing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Antlia 3nm H-Beta Pro filter for visual observation?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. Antlia lists \u003cstrong\u003enight visual observation\u003c\/strong\u003e as not recommended for this filter. It is designed for astrophotography of deep-sky objects that contain H-Beta emissions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the \u0026gt;OD5 blocking on the Antlia H-Beta Pro improve my images?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eOD5 blocking\u003c\/strong\u003e means out-of-band light, such as light pollution outside the passband, is reduced to 0.001% (a factor of 100,000) across 300-1100nm. Antlia rates this as ensuring an excellent signal-to-noise ratio and minimizing interference from other wavelengths.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Antlia 3nm H-Beta Pro work well with my f\/3.5 Newtonian astrograph?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. Antlia states that all its narrowband Pro filters can be used \u003cstrong\u003edown to f\/3\u003c\/strong\u003e with minimal loss of signal, so an f\/3.5 system is within that range.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the benefit of the single substrate design of the Antlia H-Beta Pro?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003esingle, non-glued substrate\u003c\/strong\u003e with a transmitted wavefront of \u003cstrong\u003eLambda\/4 or better\u003c\/strong\u003e is used to eliminate internal reflections. Together with a steep spectral profile that minimizes halos around bright stars, Antlia says this optical reliability reduces post-image processing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Antlia 3nm H-Beta Pro filter safe for solar imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003eNo.\u003c\/strong\u003e Antlia lists solar imaging as not recommended and warns: DO NOT LOOK AT THE SUN WITH THIS FILTER DIRECTLY. Serious eye damage will result if you fail to observe the warning. It is designed for imaging deep-sky objects that contain H-Beta emissions.\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-Beta Narrowband (3nm Pro series)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCentral Wavelength (CWL)\u003c\/td\u003e\n\u003ctd\u003e486.1nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandpass (FWHM)\u003c\/td\u003e\n\u003ctd\u003e3nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak Transmission\u003c\/td\u003e\n\u003ctd\u003e88%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Range\u003c\/td\u003e\n\u003ctd\u003e300-1100nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Depth\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;OD5 (0.001%)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecommended F-Ratio\u003c\/td\u003e\n\u003ctd\u003eUsable down to f\/3 with minimal loss of signal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Size\u003c\/td\u003e\n\u003ctd\u003e2\" Mounted (M48x0.75 Threads)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Thickness\u003c\/td\u003e\n\u003ctd\u003e2mm +\/-0.05mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSubstrate\u003c\/td\u003e\n\u003ctd\u003eOptical, single \/ non-glued\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurface Quality\u003c\/td\u003e\n\u003ctd\u003e60\/40 (per MIL-O-13830)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmitted Wavefront\u003c\/td\u003e\n\u003ctd\u003eLambda\/4 or better\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallelism\u003c\/td\u003e\n\u003ctd\u003e\u0026lt; 30 arcseconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUsage Warning\u003c\/td\u003e\n\u003ctd\u003eNot recommended for solar imaging or night visual observation. Do not look at the Sun with this filter directly.\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\"\u003eAntlia 3nm Narrowband H-Beta Pro Filter - 2\"\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\n3-Year Manufacturer Warranty against Delamination.\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Antlia","offers":[{"title":"2\" Mounted","offer_id":51932624322845,"sku":"ANT-HB-3NM-2","price":395.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/antlia-src-o4IypmAQwyQ84yQ8_2328020a-7b3a-4ad6-b185-89aa4a50f124.jpg?v=1792549993","url":"https:\/\/davidastro.com\/fr-int\/products\/antlia-3nm-narrowband-h-beta-pro-filter","provider":"David Astro","version":"1.0","type":"link"}