{"product_id":"daystar-quantum-calcium-ii-k-2a-solar-filter-ck2auni","title":"DayStar Quantum Calcium II K-Line 2Å Solar Filter — Reveal Solar Active Regions and Chromospheric Detail in Calcium Light","description":"\u003cp\u003eThe calcium K line at 393.4nm is one of the most scientifically productive solar wavelengths — used by professional observatories from Meudon to BBSO for chromospheric mapping and network studies since the 19th century. The DayStar Quantum 2Å Ca II K filter resolves chromospheric structures including the network, plage regions, and active region dynamics with outstanding clarity. At 2Å, this filter delivers meaningful contrast over the photospheric background while preserving chromospheric signal, making it suitable for high-resolution imaging programs. Note: requires telescope optics with good near-UV transmission. ERF required. Ships free to the US.\u003c\/p\u003e\u003ctable style=\"width:100%;border-collapse:collapse;margin-top:24px;font-size:14px;line-height:1.5;\"\u003e\n\u003cthead\u003e\u003ctr\u003e\u003cth colspan=\"2\" style=\"text-align:left;padding:10px 14px;background:#f7f7f7;border-bottom:2px solid #ddd;font-size:15px;font-weight:600;\"\u003eSpecifications\u003c\/th\u003e\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;width:44%;\"\u003eSKU\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003eCK2AUNI\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;\"\u003eWavelength\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003eCa II K-line (393.4nm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;\"\u003eFilter Type\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003eFabry-Pérot etalon (electrically heated for thermal stability, electronically tunable)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;\"\u003eBandpass (FWHM)\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003e2Å — higher contrast than Ca II H 5Å; chromospheric network and plage structure clearly resolved\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;\"\u003eBest For\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003eChromospheric network, plage and active region detail, multi-wavelength solar programs, high-resolution Ca II imaging\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;\"\u003eWavelength Display\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003eLive LCD readout, accurate to 0.1Å\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;\"\u003eTuning\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003eElectronic wavelength control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003e12VDC (100–240VAC supply included with US, EU, UK, and AU adapters)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;\"\u003eUV Transmission Note\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003eTelescope optics must transmit at 393.4nm; cemented objectives and many achromats attenuate near-UV significantly\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;font-weight:600;color:#444;\"\u003eERF Required\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;border-bottom:1px solid #efefef;\"\u003eYes — front-mount Energy Rejection Filter required; sold separately\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 14px;font-weight:600;color:#444;\"\u003eWhat's in the Box\u003c\/td\u003e\n\u003ctd style=\"padding:8px 14px;\"\u003eQuantum Ca II K-Line 2Å filter, 100–240VAC power supply with international adapters (US, EU, UK, AU)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Daystar","offers":[{"title":"Default Title","offer_id":44577825685538,"sku":"CK2AUNI","price":17990.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0560\/6968\/5282\/files\/DayStar_Quantum_Calcium_II_K_2_Solar_Filter_See_Fine_Solar_Surface_Detail_in_Calcium_K_Light_for_Advanced_Sun_Viewing_CK2AUNI.jpg?v=1774187413","url":"https:\/\/telescopewolves.com\/products\/daystar-quantum-calcium-ii-k-2a-solar-filter-ck2auni","provider":"Telescope Wolves","version":"1.0","type":"link"}