{"product_id":"lunt-40mm-center-obstructed-h-alpha-filter-set","title":"Lunt 40mm Center Obstructed H-Alpha Filter Set","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\u003eTurn Your Refractor Into A Solar Scope\u003c\/h2\u003e\n        \u003cp\u003eThis 40mm center obstructed H-alpha set from Lunt mounts over the centre of your existing refractor objective, converting a night sky instrument into a solar telescope in seconds. The 40mm etalon delivers a bandpass below 0.65 Angstrom at 656.28 nm, so prominences, filaments, active regions and chromospheric texture all come into view without a dedicated solar tube.\u003c\/p\u003e\n    \u003cp\u003eTuning is by tilt, so you angle the housing to centre the hydrogen alpha line and start observing. There are no pressure systems, no air pumps and no external controls to manage. A centre mounted foot supports the etalon, which means the filter carries a central obstruction; plan your aperture and contrast expectations around that design choice.\u003c\/p\u003e\n    \u003cp\u003eEach set ships with your choice of a B600 or B1200 blocking filter and one machined adapter plate sized to your telescope, included in the set. The plate is matched to the outside diameter of your dew shield, so to measure for your adapter plate take a measurement of the outside diameter of the dew shield on your refractor telescope. Nine plate steps run from 55 to 60 mm up to 95 to 100 mm, covering objective housings up to 4 inches. Removal takes seconds when the refractor is needed for night use.\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\/IMG_6139-min.jpg?v=1764862773\" alt=\"Lunt LS40F front mounted center obstructed hydrogen alpha etalon filter set\"\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\u003eFront Mounted\u003c\/b\u003e - etalon sits over the centre of your existing refractor objective and lifts off in seconds\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eBandpass\u003c\/b\u003e - rated below 0.65 Angstrom at the 656.28 nm hydrogen alpha line\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eTilt Tuned\u003c\/b\u003e - wavelength control by angling the housing, with no pressure or pump hardware\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eBlocking Filter Choice\u003c\/b\u003e - supplied with either a B600 or a B1200 blocking filter\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eAdapter Plate Included\u003c\/b\u003e - one plate machined to the outside diameter of your dew shield, from 55 mm to 100 mm, comes with the set\u003c\/li\u003e\n      \u003cli\u003e\n\u003cb\u003eCentre Obstruction\u003c\/b\u003e - a central support foot holds the etalon, so the clear aperture is obstructed at the middle\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\/IMG_6146-min.jpg?v=1764862773\" alt=\"Second view of the Lunt 40mm center obstructed front mounted etalon housing and adapter plate\"\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\u003eFront mounted center obstructed hydrogen alpha etalon filter set\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eEtalon Aperture\u003c\/td\u003e\n\u003ctd\u003e40 mm, center obstructed by the support foot\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\u003eBandpass\u003c\/td\u003e\n\u003ctd\u003eLess than 0.65 Angstrom\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eTuning\u003c\/td\u003e\n\u003ctd\u003eTilt tuned\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eBlocking Filter Options\u003c\/td\u003e\n\u003ctd\u003eB600 with 6 mm clear aperture, or B1200 with 12 mm clear aperture\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eB600 Suitability\u003c\/td\u003e\n\u003ctd\u003eLunt lists the included B600 for focal lengths up to 540 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eB1200 Suitability\u003c\/td\u003e\n\u003ctd\u003eLunt lists the B1200 for visual use to 1080 mm and imaging to 540 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eAdapter Plate\u003c\/td\u003e\n\u003ctd\u003eOne plate included with the set, chosen at checkout\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eAdapter Plate Sizing\u003c\/td\u003e\n\u003ctd\u003eMeasured on the outside diameter of the dew shield on your refractor, ranges 55-100 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eAdapter Plate Sizes Published\u003c\/td\u003e\n\u003ctd\u003e55-60, 60-65, 65-70, 70-75, 75-80, 80-85, 85-90, 90-95 and 95-100 mm, taken on the dew shield outer diameter\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eAdapter Plate Codes\u003c\/td\u003e\n\u003ctd\u003eLS40-CO-AP5560 through LS40-CO-AP95100\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eObjective Cell Limit\u003c\/td\u003e\n\u003ctd\u003eObjective housings up to 4 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eUse\u003c\/td\u003e\n\u003ctd\u003eVisual and imaging\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eModel \/ SKU\u003c\/td\u003e\n\u003ctd\u003eLS40F-CO-B600 and LS40F-CO-B1200, plus adapter plate codes LS40-CO-AP5560 through LS40-CO-AP95100\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eStorefront Listing\u003c\/td\u003e\n\u003ctd\u003ePublished as Lunt LS40F Hydrogen-Alpha Front-Mounted Etalon System B600 and B1200\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eShipping Weight\u003c\/td\u003e\n\u003ctd\u003eNot published\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":"B600 Blocking Filter \/ 55-60mm","offer_id":53917615226991,"sku":"LS40F-CO-B600+LS40-CO-AP5560","price":845.99,"currency_code":"USD","in_stock":true},{"title":"B600 Blocking Filter \/ 60-65mm","offer_id":53917615259759,"sku":"LS40F-CO-B600+LS40-CO-AP6065","price":845.99,"currency_code":"USD","in_stock":true},{"title":"B600 Blocking Filter \/ 65-70mm","offer_id":53917615292527,"sku":"LS40F-CO-B600+LS40-CO-AP6570","price":845.99,"currency_code":"USD","in_stock":true},{"title":"B600 Blocking Filter \/ 70-75mm","offer_id":53917615325295,"sku":"LS40F-CO-B600+LS40-CO-AP7075","price":845.99,"currency_code":"USD","in_stock":true},{"title":"B600 Blocking Filter \/ 75-80mm","offer_id":53917615358063,"sku":"LS40F-CO-B600+LS40-CO-AP7580","price":845.99,"currency_code":"USD","in_stock":true},{"title":"B600 Blocking Filter \/ 80-85mm","offer_id":53917615390831,"sku":"LS40F-CO-B600+LS40-CO-AP8085","price":845.99,"currency_code":"USD","in_stock":true},{"title":"B600 Blocking Filter \/ 85-90mm","offer_id":53917615423599,"sku":"LS40F-CO-B600+LS40-CO-AP8590","price":845.99,"currency_code":"USD","in_stock":true},{"title":"B600 Blocking Filter \/ 90-95mm","offer_id":53917615456367,"sku":"LS40F-CO-B600+LS40-CO-AP9095","price":845.99,"currency_code":"USD","in_stock":true},{"title":"B600 Blocking Filter \/ 95-100mm","offer_id":53917615489135,"sku":"LS40F-CO-B600+LS40-CO-AP95100","price":845.99,"currency_code":"USD","in_stock":true},{"title":"B1200 Blocking Filter \/ 55-60mm","offer_id":53917615521903,"sku":"LS40F-CO-B1200+LS40-CO-AP5560","price":945.99,"currency_code":"USD","in_stock":true},{"title":"B1200 Blocking Filter \/ 60-65mm","offer_id":53917615554671,"sku":"LS40F-CO-B1200+LS40-CO-AP6065","price":945.99,"currency_code":"USD","in_stock":true},{"title":"B1200 Blocking Filter \/ 65-70mm","offer_id":53917615587439,"sku":"LS40F-CO-B1200+LS40-CO-AP6570","price":945.99,"currency_code":"USD","in_stock":true},{"title":"B1200 Blocking Filter \/ 70-75mm","offer_id":53917615620207,"sku":"LS40F-CO-B1200+LS40-CO-AP7075","price":945.99,"currency_code":"USD","in_stock":true},{"title":"B1200 Blocking Filter \/ 75-80mm","offer_id":53917615652975,"sku":"LS40F-CO-B1200+LS40-CO-AP7580","price":945.99,"currency_code":"USD","in_stock":true},{"title":"B1200 Blocking Filter \/ 80-85mm","offer_id":53917615685743,"sku":"LS40F-CO-B1200+LS40-CO-AP8085","price":945.99,"currency_code":"USD","in_stock":true},{"title":"B1200 Blocking Filter \/ 85-90mm","offer_id":53917615718511,"sku":"LS40F-CO-B1200+LS40-CO-AP8590","price":945.99,"currency_code":"USD","in_stock":true},{"title":"B1200 Blocking Filter \/ 90-95mm","offer_id":53917615751279,"sku":"LS40F-CO-B1200+LS40-CO-AP9095","price":945.99,"currency_code":"USD","in_stock":true},{"title":"B1200 Blocking Filter \/ 95-100mm","offer_id":53917615784047,"sku":"LS40F-CO-B1200+LS40-CO-AP95100","price":945.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0717\/7968\/0367\/files\/IMG_6139-min.jpg?v=1785527527","url":"https:\/\/telescopedepot.com\/products\/lunt-40mm-center-obstructed-h-alpha-filter-set","provider":"Telescope Depot","version":"1.0","type":"link"}