{"product_id":"altair-ha-oiii-dualband-ultra-4nm-certified-cmos-filter-2-pre-owned","title":"Altair Ha Oiii DualBand ULTRA 4nm CERTIFIED CMOS Filter 2\" (Pre-owned)","description":"\u003cp\u003e\u003cspan style=\"color: rgb(255, 0, 0);\"\u003eUsed filter, in great condition!\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003eThe Altair Dual-Band ULTRA Ha Oiii nebula filter comes with a high resolution spectrographic test report.\u003c\/p\u003e\n\u003cp\u003eDesigned for imaging in extreme light pollution, E.g. in a major city, with a colour CMOS camera. \u003c\/p\u003e\n\u003cp\u003eThis filter transmits only the H and Oiii light from emission nebulae, with almost total suppression of unwanted light, with OD6 (0.0001%) over the majority of unwanted visual wavelengths* for ultimate contrast. \u003c\/p\u003e\n\u003cul\u003e\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eUSA customers: \u003c\/strong\u003eThis product can be shipped to the USA, or ordered from our US dealer \u003ca href=\"https:\/\/astroworldtelescopes.com\/\" target=\"_blank\"\u003eAstroworld Telescopes\u003c\/a\u003e.\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eGermany\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003e- \u003ca href=\"https:\/\/www.apm-telescopes.net\/en\/altair-astro\" target=\"_blank\"\u003eAPM Germany\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eFrance\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003e- \u003ca href=\"https:\/\/www.pierro-astro.com\/materiel-astronomique\/marques\/altair-astro\" target=\"_blank\"\u003ePierro Astro\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eIn a process pioneered by Altair, each individual filter in our certified range has an\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eindividual spectrographic test report with 0.1nm true resolution, unique to that particular filter.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThis is not a simulation, nor the overly optimistic marketing you tend to get with foreign filters - such as those advertised at 5nm FWHM but which actually have 6-7nm FWHM, and which have generic test reports.\u003c\/p\u003e\n\u003cp\u003eNarrowband Bi-Colour imaging is a growing new trend in astrophotography, especially popular in light polluted areas, or bright moonlight. First Altair brought you the TriBand and Quad Band filters, now we have the DualBand Ultra for the most extreme light pollution suppression.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAltair DualBand 4nm Filter Product Features:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eCapture the two main emission nebulae bands at the same time, whilst suppressing light pollution, moonlight, and airglow.\u003c\/li\u003e\n\u003cli\u003eMore data in less time, opening up your imaging window, even into the summer months when it isn't quite dark yet.\u003c\/li\u003e\n\u003cli\u003eExtremely steep bandpass yields maximum contrast in extreme light pollution: 4nm FHWM centred on 500.7nm Oiii wavelength, and 4nm FHWM centred on the 656.3nm Ha wavelength.\u003c\/li\u003e\n\u003cli\u003eHalo suppression anti-reflective coating.\u003c\/li\u003e\n\u003cli\u003eCan be used with One Shot Colour (OSC) CMOS or mono astronomical cameras for luminance data.\u003c\/li\u003e\n\u003cli\u003eIncludes UVIR blocking for both modified and un-modified DSLR cameras.\u003c\/li\u003e\n\u003cli\u003eBest performance at focal ratios as fast as F4.0, optimised at F4.8 or slower, with contrast increasing as focal ratio increases. Faster than F3.5 requires an Altair Pre-Shifted filter (please get in touch for more info). \u003ca href=\"https:\/\/www.altairastro.help\/info-instructions\/cmos\/affects-of-telescope-focal-ratio-on-light-pollution-filter-performance\/\" target=\"_blank\"\u003eMore info about light pollution filter performance and focal ratio here.\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003eThe 2\" filter has standard M48x0.75mm thread, and fits inside the Altair Magnetic Filter holders, plus the Altair Canon \/ Nikon DSLR lens to astro CMOS adaptors. \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eAltair 4nm Ha Oiii DualBand ULTRA Filter Technical Specifications:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e1st band, Oiii CWL500.7nm FWHM 4nm tolerance ~0.5nm, T% 88%~91%\u003c\/li\u003e\n\u003cli\u003e2nd band, Ha CWL 656.3nm FWHM 4nm tolerance ~0.5nm T% 90%~94%\u003c\/li\u003e\n\u003cli\u003eOD6 (0.0001%) from 200-760nm (visual wavelengths), and OD4.5 (0.003%) average from 800-1100nm (IR wavelengths) for the ultimate contrast. *Based on a test of 10 random samples in  batch 09-2023.\u003c\/li\u003e\n\u003cli\u003e1.85mm thick optical glass with 30 arc sec parallelism.\u003c\/li\u003e\n\u003cli\u003eSi02 \"hard\" overcoat with UVIR Block and Anti-Reflection Coating for durability.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How do OSC Narrowband filters work?\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eAltair OSC narrowband filters work by isolating the primary nebulae emission zones in the red and blue wavelengths, and separating them into two main \"zones\" with a wide separation for easy capture with a colour camera - all in one exposure! Not only is capture more convenient with one filter, but processing is easy too, thanks to the wide separation of the green\/blue and red \"zones\". Light pollution control is extremely effective and even LED light pollution is significantly reduced.\u003cbr\u003e\u003c\/p\u003e","brand":"altair","offers":[{"title":"Default Title","offer_id":42846777770097,"sku":"USED121107","price":288.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/20251211_144641.jpg?v=1776459320","url":"https:\/\/khanscope.com\/en-fr\/products\/altair-ha-oiii-dualband-ultra-4nm-certified-cmos-filter-2-pre-owned","provider":"Khan Scope Centre","version":"1.0","type":"link"}