{"product_id":"antlia-filtro-cak-3nm-125","title":"Antlia CaK 3nm 393.3nm Filter 1.25\"","description":"\u003ch2\u003eAntlia CaK 3nm 393.3nm Filter 1.25\" – Ultra-Narrow Band for Solar Imaging\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eAntlia CaK 3nm filter\u003c\/strong\u003e is an ultra-narrow bandpass filter centered on the ionized Calcium II (CaK) line at \u003cstrong\u003e393.3nm\u003c\/strong\u003e, built on a heat-resistant, double-polished substrate with the most advanced multi-coatings. It is designed to maximize contrast for high-resolution imaging of sunspots, solar surface granulation and other features prominent in CaK light.\u003c\/p\u003e\n\u003cp\u003eThe high blocking specification – OD5 (0.001%) between 200 and 1200nm and OD3 (0.1%) between 1200 and 1500nm – delivers exceptional resolution for imaging. The CaK band (393nm) makes solar features almost invisible to the human eye due to low sensitivity and poor resolving ability at this frequency: the filter is therefore \u003cstrong\u003enot recommended for visual observation\u003c\/strong\u003e, but designed for imaging with cameras whose spectral response goes well beyond human vision.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWarning:\u003c\/strong\u003e the CaK 3nm 393.3nm filter must be used \u003cstrong\u003eexclusively in combination with a Herschel wedge\u003c\/strong\u003e. Never look at the sun with the CaK filter alone: even though you can't perceive it, a significant amount of harmful UV radiation can still reach the eye.\u003c\/p\u003e\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003e3nm\u003c\/strong\u003e bandpass, centered on the Calcium K line at 393.3nm\u003c\/li\u003e\n\u003cli\u003eHeat-resistant substrate, double-polished\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eOD5 (0.001%)\u003c\/strong\u003e blocking between 200–1200nm, \u003cstrong\u003eOD3 (0.1%)\u003c\/strong\u003e between 1200–1500nm\u003c\/li\u003e\n\u003cli\u003eAdvanced multi-coating for maximum contrast\u003c\/li\u003e\n\u003cli\u003e1.25\" mount (M28.5x0.6)\u003c\/li\u003e\n\u003cli\u003eFor use only with a Herschel wedge\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\u003ctd\u003eUltra-narrow band CaK (Calcium II K)\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eCenter wavelength\u003c\/strong\u003e\u003c\/td\u003e\u003ctd\u003e393.3nm\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eBandpass (FWHM)\u003c\/strong\u003e\u003c\/td\u003e\u003ctd\u003e3nm\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eOut-of-band blocking\u003c\/strong\u003e\u003c\/td\u003e\u003ctd\u003eOD5 (0.001%) @ 200–1200nm; OD3 (0.1%) @ 1200–1500nm\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eFormat\u003c\/strong\u003e\u003c\/td\u003e\u003ctd\u003e1.25\" (mounted, M28.5x0.6)\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eSubstrate\u003c\/strong\u003e\u003c\/td\u003e\u003ctd\u003eHeat-resistant optical glass, double-polished\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eIntended use\u003c\/strong\u003e\u003c\/td\u003e\u003ctd\u003eImaging only, exclusively with a Herschel wedge\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eVisual observation\u003c\/strong\u003e\u003c\/td\u003e\u003ctd\u003eNot recommended\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eWarranty\u003c\/strong\u003e\u003c\/td\u003e\u003ctd\u003e3 years against delamination\u003c\/td\u003e\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e","brand":"Antlia","offers":[{"title":"Default Title","offer_id":58540596232523,"sku":"ANA-CAK3-1","price":349.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0886\/1981\/1147\/files\/Antlia-Ca-K-3nm-1-25.jpg?v=1790069800","url":"https:\/\/adriasky.it\/en\/products\/antlia-cak-3nm-filter-125-in","provider":"Adriasky","version":"1.0","type":"link"}