{"product_id":"antlia-3nm-sii-pro-series-filter-31-mm-sii-pro-3nm-31","title":"Antlia 3nm SII Pro Series Filter - 31 mm - SII-PRO-3NM-31","description":"\u003cp\u003e\u003cspan\u003eThis very narrowband 3 nm SII filter from Antlia is part of their Pro series and is of the 31 mm unmounted variety.  It is normally used in a 1.25\"\/31mm filter wheel, where it drops into place.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 style=\"text-align: center;\"\u003eAntlia 3nm Pro Series Sulfur II Filter - 31 mm Unmounted\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eThis Antlia \u003c\/span\u003e\u003cspan\u003eSII \u003c\/span\u003e\u003cspan\u003ePro narrowband filter optimizes the FWHM (full width half maximum) to a 3nm bandpass. As the bandwidth becomes narrower, the \u003c\/span\u003e\u003cspan\u003e3nm \u003c\/span\u003e\u003cspan\u003ePro \u003c\/span\u003e\u003cspan\u003enarrowband \u003c\/span\u003e\u003cspan\u003efilters enhance contrast of emission targets by lowering the unwanted background signal. Antlia SII\u003c\/span\u003e\u003cspan\u003e 3nm Pro\u003c\/span\u003e\u003cspan\u003e filter is designed to deliver 88% transmission at the 671.6nm line\u003c\/span\u003e\u003cspan\u003e which\u003c\/span\u003e\u003cspan\u003e provides you with the maximum signal and well defined nebulae structures\u003c\/span\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eConventional broader narrowband filters cause a heavy loss in transmission due to the strong (Center Wavelength (CWL)-shift\u003c\/span\u003e\u003cspan\u003e. \u003c\/span\u003e\u003cspan\u003eWe guarantee T\u0026gt;88% within 1nm range of the center bandwidth\u003c\/span\u003e\u003cspan\u003e,\u003c\/span\u003e\u003cspan\u003ewhich means that the 3nm Pro narrowband filter can guarantee high transmittance for working with both long focal ratios and fast optical systems\u003c\/span\u003e\u003cspan\u003e. B\u003c\/span\u003e\u003cspan\u003elue\u003c\/span\u003e\u003cspan\u003e-\u003c\/span\u003e\u003cspan\u003eshift data show that Antlia 3nm Pro filters can be used with nearly all systems as fast as f\/3 with minimal loss in emission signal\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eand meets the requirements of fast optics like Hyperstar and RASA.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe out of band blocking specification is rated OD\u003c\/span\u003e\u003cspan\u003e5\u003c\/span\u003e\u003cspan\u003e (0.\u003c\/span\u003e\u003cspan\u003e00\u003c\/span\u003e\u003cspan\u003e1%) which delivers an excellent \u003c\/span\u003e\u003cspan\u003eSNR(\u003c\/span\u003e\u003cspan\u003esignal to noise ratio\u003c\/span\u003e\u003cspan\u003e)\u003c\/span\u003e\u003cspan\u003e and effective cut-off rate to minimize interference from other wavelengths.\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eImproved\u003c\/span\u003e\u003cspan\u003e sharp cut-off\u003c\/span\u003e\u003cspan\u003e astrophotography 3nm Pro filters are designed to minimize halos around bright stars.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eApplication and Performance:\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eHigh transmittance and smallest bandwidth\u003c\/span\u003e\u003cspan\u003e to maximize\u003c\/span\u003e\u003cspan\u003e contrast\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eSteep spectral profile minimizes halos around bright stars\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA single substrate to eliminate internal reflections   \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eNarrowband Objects: SII Emission Nebulae, Planetary, Wolf-Rayet Nebulae and Supernova Remnants\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eUse in light polluted areas and dark sites\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eExtend imaging time when the moon is up\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAll Antlia narrowband Pro filters can be used \u003c\/span\u003e\u003cspan\u003edown \u003c\/span\u003e\u003cspan\u003eto F\/3 with slight loss of signal\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAll Antlia Narrowband filters are edge blackened to eliminate internal reflections from stray light\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eSuperior optical reliability reduces post image processing\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis filter is not suited to deep sky objects that do not contain \u003c\/span\u003e\u003cspan\u003eSII\u003c\/span\u003e\u003cspan\u003e emissions.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\n\u003cspan\u003eTechnical Specifications\u003c\/span\u003e\u003cspan\u003e:\u003c\/span\u003e\n\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eBasic Substrate:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Schott optical substrate\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFilter Thickness：\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e2mm+\/-0.05mm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFWHM (Full width at half maximum): \u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e3nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCWL (Central Wavelength)\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: 671.6nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003ePeak Transmission:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e ＞88%\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eBlocking: \u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e\u0026gt; 5 OD(0.001% out of band blocking) @ 300-1000nm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eSurface Quality: \u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003eS\/D (scratch\/dig)= 60\/40 (Refer to MIL-O-13830)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTransmitted Wavefront: \u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003eLambda\/4 or better.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eParallelism: \u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003eless than 30 arcsec\u003c\/span\u003e\u003c\/p\u003e","brand":"Antlia","offers":[{"title":"Default Title","offer_id":43012591976561,"sku":"ATL-SII-PRO-3NM-31","price":250.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/SII_Pro_31mm.jpg?v=1776459209","url":"https:\/\/khanscope.com\/fr-fr\/products\/antlia-3nm-sii-pro-series-filter-31-mm-sii-pro-3nm-31","provider":"Khan Scope Centre","version":"1.0","type":"link"}