{"product_id":"lunt-h-alpha-blocking-filter","title":"Lunt H-Alpha Blocking Filter","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\u003eChoose The Right Blocking Filter Aperture\u003c\/h2\u003e\n        \u003cp\u003eA Lunt blocking filter is required with every Lunt hydrogen alpha etalon or telescope. It is not just a stop; the housing carries an additional filter stack that makes the package safe and gives the final image its contrast. Lunt only warrants safety and performance when one of its own blocking filters sits in the optical path.\u003c\/p\u003e\n    \u003cp\u003eClear aperture sets how much of the light cone gets through. B600 gives 6 mm, B1200 gives 12 mm, B1800 gives 18 mm and B3400 gives 34 mm. Larger apertures hold a fully illuminated field at longer focal lengths, which is what full disc imaging with a bigger sensor needs. Match the size to your telescope focal length.\u003c\/p\u003e\n    \u003cp\u003eHousings come in three styles. The s versions are 2 inch straight through tubes with T2 and 2 inch connections. The d1 versions are star diagonals with a 1.25 inch eyepiece holder and a T2 connection, and the d2 versions are star diagonals with a 2 inch eyepiece holder and T2. For imaging, step up one size from the visual recommendation.\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\/B600-Blocking-Filter-Profile.jpg?v=1743112814\" alt=\"Profile view of a Lunt B600 hydrogen alpha blocking filter 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\u003eSafety Critical\u003c\/b\u003e - required in the optical path of every Lunt hydrogen alpha etalon or telescope\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eFour Clear Apertures\u003c\/b\u003e - 6 mm, 12 mm, 18 mm and 34 mm to suit different focal lengths\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eStraight Through\u003c\/b\u003e - the s housings are 2 inch extension tubes with T2 and 2 inch connections\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eStar Diagonal\u003c\/b\u003e - d1 and d2 housings add a star diagonal with a 1.25 inch or 2 inch eyepiece holder\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eImaging Headroom\u003c\/b\u003e - step one size up from the visual recommendation to allow for extra back focus\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eFull Disc Imaging\u003c\/b\u003e - the larger apertures keep the field fully illuminated for big sensor full disc work\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\/B1800-Blocking-Filter-3qt-Front.jpg?v=1743112814\" alt=\"Three quarter front view of a Lunt B1800 hydrogen alpha blocking filter in a star diagonal housing\"\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\u003eHydrogen alpha blocking filter module\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eWavelength\u003c\/td\u003e\n\u003ctd\u003eHydrogen alpha, 656.28 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eB600\u003c\/td\u003e\n\u003ctd\u003e6 mm clear aperture, visual to 600 mm focal length, imaging to 400 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eB1200\u003c\/td\u003e\n\u003ctd\u003e12 mm clear aperture, visual to 1200 mm focal length, imaging to 600 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eB1800\u003c\/td\u003e\n\u003ctd\u003e18 mm clear aperture, visual to 1800 mm focal length, imaging to 1200 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eB3400\u003c\/td\u003e\n\u003ctd\u003e34 mm clear aperture, visual to 3400 mm focal length, imaging to 1800 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eStraight Through Housing\u003c\/td\u003e\n\u003ctd\u003e2 inch extension tube with T2 and 2 inch connections, suffix s\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e1.25 Inch Diagonal Housing\u003c\/td\u003e\n\u003ctd\u003eStar diagonal with 1.25 inch eyepiece holder and T2 connection, suffix d1\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e2 Inch Diagonal Housing\u003c\/td\u003e\n\u003ctd\u003eStar diagonal with 2 inch eyepiece holder and T2 connection, suffix d2\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eB3400 Housing\u003c\/td\u003e\n\u003ctd\u003e2 inch straight through extension tube only, no diagonal option published\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eCompatibility\u003c\/td\u003e\n\u003ctd\u003eLunt hydrogen alpha etalon filters and Lunt solar telescopes\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eAdditional Sizes Published\u003c\/td\u003e\n\u003ctd\u003eA B400 4 mm and a B500 5 mm filter, both in 1.25 inch diagonals, also appear on the Lunt storefront\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eStorefront SKU Format\u003c\/td\u003e\n\u003ctd\u003eStraight through options are listed as B600s2, B1200s2 and B1800s2, and the 34 mm filter as B3400\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eModel \/ SKU\u003c\/td\u003e\n\u003ctd\u003eB600s, B600d1, B600d2, B1200s, B1200d1, B1200d2, B1800s, B1800d1, B1800d2, B3400s2\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eShipping Weight\u003c\/td\u003e\n\u003ctd\u003e2 lb, published as 907 grams for every variant\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":"B600s 6mm, 2\" Straight Through","offer_id":53917630201967,"sku":"B600s","price":395.99,"currency_code":"USD","in_stock":true},{"title":"B600d1 6mm, 1.25\" Star Diagonal","offer_id":53917630234735,"sku":"B600d1","price":395.99,"currency_code":"USD","in_stock":true},{"title":"B600d2 6mm, 2\" Star Diagonal","offer_id":53917630267503,"sku":"B600d2","price":395.99,"currency_code":"USD","in_stock":true},{"title":"B1200s 12mm, 2\" Straight Through","offer_id":53917630300271,"sku":"B1200s","price":495.99,"currency_code":"USD","in_stock":true},{"title":"B1200d1 12mm, 1.25\" Star Diagonal","offer_id":53917630333039,"sku":"B1200d1","price":495.99,"currency_code":"USD","in_stock":true},{"title":"B1200d2 12mm, 2\" Star Diagonal","offer_id":53917630365807,"sku":"B1200d2","price":495.99,"currency_code":"USD","in_stock":true},{"title":"B1800s 18mm, 2\" Straight Through","offer_id":53917630398575,"sku":"B1800s","price":795.99,"currency_code":"USD","in_stock":true},{"title":"B1800d1 18mm, 1.25\" Star Diagonal","offer_id":53917630431343,"sku":"B1800d1","price":795.99,"currency_code":"USD","in_stock":true},{"title":"B1800d2 18mm, 2\" Star Diagonal","offer_id":53917630464111,"sku":"B1800d2","price":795.99,"currency_code":"USD","in_stock":true},{"title":"B3400s2 34mm, 2\" Straight Through","offer_id":53917630496879,"sku":"B3400s2","price":2495.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0717\/7968\/0367\/files\/B600-Blocking-Filter-Profile.jpg?v=1785527527","url":"https:\/\/telescopedepot.com\/products\/lunt-h-alpha-blocking-filter","provider":"Telescope Depot","version":"1.0","type":"link"}