{"product_id":"lunt-calcium-k-blocking-filter-module","title":"Lunt Calcium K Blocking Filter Module","description":"\u003cdiv class=\"kt-page\"\u003e\n\n\u003cstyle\u003e\n.kt-page{--kt-primary:#030B1C;--kt-accent:#2E7FBF;max-width:1100px;margin:0 auto;font-family:inherit;}\n.kt-page.kt-page--wide{max-width:1600px;}\n.kt-page .kt-hero{display:flex;align-items:center;gap:40px;margin-bottom:40px;}\n.kt-page .kt-hero-copy{flex:1 1 55%;}\n.kt-page .kt-hero-img{flex:1 1 40%;text-align:center;}\n.kt-page .kt-sq{width:100%;max-width:420px;aspect-ratio:1\/1;margin:0 auto;background:#ffffff;border-radius:6px;display:flex;align-items:center;justify-content:center;overflow:hidden;}\n.kt-page .kt-sq img{max-width:92%;max-height:92%;width:auto;height:auto;object-fit:contain;}\n.kt-page .kt-hero-copy h2{font-size:26px;margin-bottom:14px;}\n.kt-page .kt-hero-copy p{font-size:16px;line-height:1.6;margin-bottom:14px;}\n.kt-page .kt-features{display:flex;align-items:flex-start;gap:40px;margin:40px 0;}\n.kt-page .kt-features-copy{flex:1 1 55%;}\n.kt-page .kt-features-img{flex:1 1 40%;text-align:center;}\n.kt-page .kt-section-heading{font-size:21px;display:inline-block;padding-bottom:8px;border-bottom:2px solid var(--kt-accent);margin-bottom:18px;}\n.kt-page .kt-feature-list{list-style:none;margin:0;padding:0;}\n.kt-page .kt-feature-list li{font-size:16px;line-height:1.5;margin-bottom:12px;padding-left:26px;position:relative;}\n.kt-page .kt-feature-list li:before{content:\"\\2713\";color:var(--kt-accent);font-weight:bold;position:absolute;left:0;}\n.kt-page .kt-feature-list b{color:#222;}\n.kt-page .kt-specs-wrap{box-sizing:border-box;}\n.kt-page .kt-specs{display:table !important;width:100% !important;border-collapse:collapse;margin:40px 0;font-size:15px;}\n.kt-page .kt-specs th,.kt-page .kt-specs td{border:2px solid #000;padding:10px 12px;text-align:left;}\n.kt-page .kt-specs th{background:var(--kt-primary) !important;color:#fff !important;font-size:16px;}\n.kt-page .kt-specs tr:nth-child(even){background:#f2f2f2;}\n.kt-page .kt-specs tr:nth-child(odd){background:#ffffff;}\n.kt-page .kt-cta{text-align:center;margin:40px 0;font-size:18px;font-weight:bold;}\n.kt-page .kt-cta-buttons{display:flex;justify-content:center;gap:16px;margin-top:16px;flex-wrap:wrap;}\n.kt-page .kt-cta-buttons a{display:inline-block;padding:12px 26px;border:2px solid var(--kt-primary);border-radius:4px;color:var(--kt-primary);text-decoration:none;font-weight:bold;font-size:15px;transition:all .15s ease;}\n.kt-page .kt-cta-buttons a:hover{background:var(--kt-primary);color:#fff;}\n.kt-page .kt-manuals a{display:block;color:var(--kt-primary);font-weight:bold;font-size:30px;text-align:left;text-decoration:none;margin-bottom:10px;}\n.kt-page .kt-manuals a:hover{color:var(--kt-accent);}\n@media (max-width:768px){\n  .kt-page .kt-hero,.kt-page .kt-features{flex-direction:column;}\n  .kt-page .kt-hero-img img,.kt-page .kt-features-img img{max-width:400px;}\n  .kt-page .kt-hero-copy p,.kt-page .kt-features-copy p{font-size:17px;}\n  .kt-page .kt-cta-buttons{display:grid;grid-template-columns:1fr 1fr;gap:12px;}\n  .kt-page .kt-cta-buttons a:nth-child(3){grid-column:1 \/ span 2;}\n  .kt-page .kt-manuals a{font-size:24px;}\n}\n\u003c\/style\u003e\n\n\u003cdiv class=\"kt-hero\"\u003e\n  \u003cdiv class=\"kt-hero-copy\"\u003e\n    \u003ch2\u003eSee The Sun In Calcium K Light\u003c\/h2\u003e\n        \u003cp\u003eThis calcium K blocking module from Lunt works at 393.4 nm, the calcium K line at the violet edge of the visible spectrum. It shows a lower, cooler layer than hydrogen alpha, where supergranulation cells and bright plage trace the magnetic network. Running CaK alongside H-alpha tells you more about the structure and depth of active regions.\u003c\/p\u003e\n    \u003cp\u003eTreat CaK as a photographic wavelength. Most adult eyes respond poorly at 393 nm because the cornea and lens yellow with age, so many observers see the violet colour but little contrast. Observers who have had cataract surgery often see far more. A camera records the detail readily, which is why the module is built around imaging.\u003c\/p\u003e\n    \u003cp\u003eThe module carries internal narrowband filters for a bandpass under 2.4 Angstrom and mounts on most standard night time refractors, or on a Lunt modular telescope in its night configuration. Pick the blocking aperture by focal length: B600 to 600 mm, B1200 to 1200 mm and B1800 to 1800 mm, each rated for apertures up to 100 mm.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"kt-hero-img\"\u003e\n    \u003cdiv class=\"kt-sq\"\u003e\n      \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/8273\/7521\/files\/CaK-Blocking-Filter-Ck-Diagonal-Profile-Lunt-Solar-Telescope-1.jpg?v=1743112811\" alt=\"Profile view of a Lunt Calcium K blocking filter module in a 2 inch star diagonal housing\"\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"kt-features\"\u003e\n  \u003cdiv class=\"kt-features-copy\"\u003e\n    \u003ch3 class=\"kt-section-heading\"\u003eKey Features\u003c\/h3\u003e\n    \u003cul class=\"kt-feature-list\"\u003e\n      \u003cli\u003e\n\u003cb\u003eCalcium K Line\u003c\/b\u003e - centred on 393.4 nm, a lower and cooler layer than the hydrogen alpha chromosphere\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eNarrow Bandpass\u003c\/b\u003e - internal narrowband filters give less than 2.4 Angstrom\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eImaging First\u003c\/b\u003e - most adult eyes respond poorly at 393 nm, so a camera is the usual detector\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eThree Apertures\u003c\/b\u003e - 6 mm, 12 mm and 18 mm modules cover focal lengths to 600, 1200 and 1800 mm\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eHousing Choice\u003c\/b\u003e - each aperture comes as a 2 inch star diagonal or a 2 inch straight through tube\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eWide Compatibility\u003c\/b\u003e - fits most standard night time refractors and Lunt modular telescopes in night configuration\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"kt-features-img\"\u003e\n    \u003cdiv class=\"kt-sq\"\u003e\n      \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/8273\/7521\/files\/CaK-Blocking-Filter-C-Straight-Through-Lunt-Solar-Telescope.jpg?v=1743112811\" alt=\"Lunt Calcium K blocking filter module in a 2 inch straight through extension tube\"\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"kt-specs-wrap\"\u003e\n\u003ctable class=\"kt-specs\"\u003e\n  \u003ctr\u003e\u003cth colspan=\"2\"\u003eSpecifications\u003c\/th\u003e\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eCalcium K blocking filter module\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eWavelength\u003c\/td\u003e\n\u003ctd\u003e393.4 nm, the calcium K line\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eBandpass\u003c\/td\u003e\n\u003ctd\u003eLess than 2.4 Angstrom\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003ePrimary Use\u003c\/td\u003e\n\u003ctd\u003eImaging, since most adult eyes respond poorly at 393 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e6 mm Diagonal Module\u003c\/td\u003e\n\u003ctd\u003e2 inch star diagonal, telescopes to 100 mm aperture and 600 mm focal length\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e6 mm Straight Module\u003c\/td\u003e\n\u003ctd\u003e2 inch straight through tube, same aperture and focal length rating\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e12 mm Diagonal Module\u003c\/td\u003e\n\u003ctd\u003e2 inch star diagonal, telescopes to 100 mm aperture and 1200 mm focal length\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e12 mm Straight Module\u003c\/td\u003e\n\u003ctd\u003e2 inch straight through tube, same aperture and focal length rating\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e18 mm Diagonal Module\u003c\/td\u003e\n\u003ctd\u003e2 inch star diagonal, telescopes to 100 mm aperture and 1800 mm focal length\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e18 mm Straight Module\u003c\/td\u003e\n\u003ctd\u003e2 inch straight through tube, listed on the storefront as LS18CaKMDs2\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e130 mm Module\u003c\/td\u003e\n\u003ctd\u003eListed as the 130mm Universal CaK Module, storefront SKU LSCaKMD, published as a single option\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eTelescope Aperture Limit\u003c\/td\u003e\n\u003ctd\u003eUp to 100 mm for the 2 inch modules\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eCompatibility\u003c\/td\u003e\n\u003ctd\u003eMost standard night time refractors and Lunt modular telescopes in night configuration\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eModel \/ SKU\u003c\/td\u003e\n\u003ctd\u003eLS6CaKMDd, LS6CaKMDs, LS12CaKMDd, LS12CaKMDs, LS18CaKMDd, LS18CaKMDs and LS130TCaKMD\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eStorefront SKU Format\u003c\/td\u003e\n\u003ctd\u003eLS6CaKMD, LS12CaKMD, LS18CaKMD, LS6CaKMDs, LS12CaKMDs, LS18CaKMDs2 and LSCaKMD\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eShipping Weight\u003c\/td\u003e\n\u003ctd\u003e2 lb for the 2 inch modules, 4 lb for the 130 mm module\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e5 years from date of purchase, original purchaser, manufacturing and workmanship defects\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\n\n\u003cp class=\"kt-cta\"\u003e\n  Talk to a Specialist\n  \u003cspan class=\"kt-cta-buttons\"\u003e\n    \u003ca href=\"\/pages\/contact\" style=\"display:inline-block;padding:12px 26px;border:2px solid var(--kt-primary);border-radius:4px;color:var(--kt-primary);text-decoration:none;font-weight:bold;\"\u003eContact Us\u003c\/a\u003e\n    \u003ca href=\"mailto:sales@telescopedepot.com\" style=\"display:inline-block;padding:12px 26px;border:2px solid var(--kt-primary);border-radius:4px;color:var(--kt-primary);text-decoration:none;font-weight:bold;\"\u003eEmail a Specialist\u003c\/a\u003e\n    \u003ca href=\"\/pages\/shipping\" style=\"display:inline-block;padding:12px 26px;border:2px solid var(--kt-primary);border-radius:4px;color:var(--kt-primary);text-decoration:none;font-weight:bold;\"\u003eShipping Info\u003c\/a\u003e\n  \u003c\/span\u003e\n\u003c\/p\u003e\n\n\u003c\/div\u003e","brand":"Lunt Solar Systems","offers":[{"title":"LS6CaKMDd 6mm, 2\" Star Diagonal","offer_id":53917532979311,"sku":"LS6CaKMDd","price":895.99,"currency_code":"USD","in_stock":true},{"title":"LS6CaKMDs 6mm, 2\" Straight Through","offer_id":53917533012079,"sku":"LS6CaKMDs","price":895.99,"currency_code":"USD","in_stock":true},{"title":"LS12CaKMDd 12mm, 2\" Star Diagonal","offer_id":53917533044847,"sku":"LS12CaKMDd","price":1495.99,"currency_code":"USD","in_stock":true},{"title":"LS12CaKMDs 12mm, 2\" Straight Through","offer_id":53917533077615,"sku":"LS12CaKMDs","price":1495.99,"currency_code":"USD","in_stock":true},{"title":"LS18CaKMDd 18mm, 2\" Star Diagonal","offer_id":53917533110383,"sku":"LS18CaKMDd","price":1695.99,"currency_code":"USD","in_stock":true},{"title":"LS18CaKMDs 18mm, 2\" Straight Through","offer_id":53917533143151,"sku":"LS18CaKMDs","price":1695.99,"currency_code":"USD","in_stock":true},{"title":"LS130TCaKMD Herschel Wedge, filter only","offer_id":53917533175919,"sku":"LS130TCaKMD","price":1995.99,"currency_code":"USD","in_stock":true},{"title":"LS130TCaKMD Herschel Wedge with LS130MT backing plate","offer_id":53917533208687,"sku":"LS130TCaKMD-BP","price":2149.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0717\/7968\/0367\/files\/CaK-Blocking-Filter-Ck-Diagonal-Profile-Lunt-Solar-Telescope-1.jpg?v=1785527446","url":"https:\/\/telescopedepot.com\/products\/lunt-calcium-k-blocking-filter-module","provider":"Telescope Depot","version":"1.0","type":"link"}