{"product_id":"baader-filtro-s-ii-ultra-narrowband-4nm","title":"Baader S-II Ultra-Narrowband Filter 4nm","description":"\u003cp\u003e\u003cstrong\u003eThe Baader S-II Ultra-Narrowband Filter 4nm\u003c\/strong\u003e is the even narrower-band version compared to the standard Narrowband (6.5nm), designed for maximum possible contrast even under heavily light-polluted skies (Bortle 9\/8\/7\/6).\u003c\/p\u003e\n\n\u003ch2\u003eWhat it's for\u003c\/h2\u003e\n\u003cp\u003eLinear filter with a 4nm FWHM passband, recommended for optical systems from f\/10 to f\/3.5. Compared to the standard Narrowband version, the narrower passband allows for even greater contrast, further reduces the apparent size of stars and reveals the finest details of emission nebulae — essential under heavy urban light pollution.\u003c\/p\u003e\n\n\u003ch2\u003eBaader CMOS-Optimized technology\u003c\/h2\u003e\n\u003cp\u003eThe filter is coated with \u003cstrong\u003eReflex-Blocker™\u003c\/strong\u003e treatment, which eliminates unwanted reflections even in the presence of auxiliary optics, and with \u003cstrong\u003eLife-Coat™\u003c\/strong\u003e technology: a hardened coating that does not flake, does not degrade and lasts the filter's entire lifetime even under the most extreme conditions. The edges are blackened all around, with a visual indicator on the front side for correct orientation during mounting. The filter is individually polished and coated, with no exposed coating edges.\u003c\/p\u003e\n\n\u003ch2\u003eAvailable formats\u003c\/h2\u003e\n\u003cp\u003eAvailable in 7 formats: 1¼\" (31.8mm), 2\" (50.8mm), 31mm, 36mm, 50.4mm, 50×50mm and 65×65mm.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eS-II Ultra-Narrowband\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCentral wavelength\u003c\/td\u003e\n\u003ctd\u003e671.7 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBandwidth (FWHM)\u003c\/td\u003e\n\u003ctd\u003e4 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecommended optical systems\u003c\/td\u003e\n\u003ctd\u003ef\/10 to f\/3.5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter thickness\u003c\/td\u003e\n\u003ctd\u003e2 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoating\u003c\/td\u003e\n\u003ctd\u003eReflex-Blocker™, Life-Coat™\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eBaader Planetarium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWho it's for\u003c\/h2\u003e\n\u003cp\u003eIdeal for astrophotographers working under heavily light-polluted skies who want the maximum possible contrast for S-II imaging, or for those who want to purchase the individual filters of the SHO palette separately to complete or replace an existing set. Compatible with filter wheels and most mono CMOS cameras.\u003c\/p\u003e","brand":"Baader-Planetarium","offers":[{"title":"1¼\" (31,8mm)","offer_id":58482441388363,"sku":"BRBP2961475","price":267.0,"currency_code":"EUR","in_stock":true},{"title":"2\" (50,8mm)","offer_id":58482444599627,"sku":"BRBP2961478","price":388.0,"currency_code":"EUR","in_stock":true},{"title":"31mm","offer_id":58482444632395,"sku":"BRBP2961476","price":286.0,"currency_code":"EUR","in_stock":true},{"title":"36mm","offer_id":58482444665163,"sku":"BRBP2961477","price":343.0,"currency_code":"EUR","in_stock":true},{"title":"50,4mm","offer_id":58482444697931,"sku":"BRBP2961479","price":418.0,"currency_code":"EUR","in_stock":true},{"title":"50x50mm","offer_id":58482444730699,"sku":"BRBP2961480","price":427.0,"currency_code":"EUR","in_stock":true},{"title":"65x65mm","offer_id":58482444763467,"sku":"BRBP2961481","price":568.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0886\/1981\/1147\/files\/baader-filtro-s-ii-ultra-narrowband-4nm-114pollice.jpg?v=1789497449","url":"https:\/\/adriasky.it\/en\/products\/baader-s-ii-ultra-narrowband-filter-4nm","provider":"Adriasky","version":"1.0","type":"link"}