{"product_id":"lunt-40mm-double-stack-filter-for-ls40tha","title":"Lunt 40mm Double Stack filter for LS40THa","description":"\u003ch2 data-start=\"0\" data-end=\"44\" style=\"text-align: center;\"\u003eLunt 40mm Double Stack Filter for LS40THa\u003c\/h2\u003e\n\u003cul data-start=\"46\" data-end=\"933\"\u003e\n\u003cli data-start=\"46\" data-end=\"121\"\u003e\n\u003cp data-start=\"48\" data-end=\"121\"\u003ePreorder notice: \u003cstrong data-start=\"65\" data-end=\"100\"\u003eships 30–60 days after checkout\u003c\/strong\u003e (estimated window)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"122\" data-end=\"257\"\u003e\n\u003cp data-start=\"124\" data-end=\"257\"\u003ePurpose-built \u003cstrong data-start=\"138\" data-end=\"162\"\u003eLS40FHa front etalon\u003c\/strong\u003e to double-stack your \u003cstrong data-start=\"184\" data-end=\"226\"\u003eLunt 40 mm dedicated H-alpha telescope\u003c\/strong\u003e for a serious contrast boost\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"258\" data-end=\"388\"\u003e\n\u003cp data-start=\"260\" data-end=\"388\"\u003e\u003cstrong data-start=\"260\" data-end=\"286\"\u003eNo central obstruction\u003c\/strong\u003e and \u003cstrong data-start=\"291\" data-end=\"315\"\u003eintegral tilt tuning\u003c\/strong\u003e maintain even illumination and let you precisely dial features on-band\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"389\" data-end=\"541\"\u003e\n\u003cp data-start=\"391\" data-end=\"541\"\u003eTighten your system from an estimated \u003cstrong data-start=\"429\" data-end=\"440\"\u003e\u0026lt;0.70 Å\u003c\/strong\u003e (single stack) down to \u003cstrong data-start=\"464\" data-end=\"476\"\u003e~\u0026lt;0.50 Å\u003c\/strong\u003e (double stack) for finer filaments, mottling, and plage detail\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"542\" data-end=\"643\"\u003e\n\u003cp data-start=\"544\" data-end=\"643\"\u003e\u003cstrong data-start=\"544\" data-end=\"572\"\u003eBlocking filter required\u003c\/strong\u003e for safe operation (Lunt BF, matched to your setup; sold separately)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"644\" data-end=\"748\"\u003e\n\u003cp data-start=\"646\" data-end=\"748\"\u003eDrop-in upgrade that \u003cstrong data-start=\"667\" data-end=\"715\"\u003edoes not change the telescope’s focal length\u003c\/strong\u003e (\u003cstrong data-start=\"717\" data-end=\"727\"\u003e400 mm\u003c\/strong\u003e remains unchanged)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"749\" data-end=\"842\"\u003e\n\u003cp data-start=\"751\" data-end=\"842\"\u003eLightweight, field-friendly design (~\u003cstrong data-start=\"788\" data-end=\"796\"\u003e1 lb\u003c\/strong\u003e)—ideal for travel and quick outreach setups\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"843\" data-end=\"933\"\u003e\n\u003cp data-start=\"845\" data-end=\"933\"\u003eStore it with your scope: \u003cstrong data-start=\"871\" data-end=\"933\"\u003efits the optional LS40 aluminum hard case with fitted foam\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch1 data-start=\"935\" data-end=\"951\"\u003eSpecifications\u003c\/h1\u003e\n\u003cul data-start=\"952\" data-end=\"1567\"\u003e\n\u003cli data-start=\"952\" data-end=\"1046\"\u003e\n\u003cp data-start=\"954\" data-end=\"1046\"\u003e\u003cstrong data-start=\"954\" data-end=\"964\"\u003eModel:\u003c\/strong\u003e LS40FHa Double Stack Solar Filter (for Lunt 40 mm dedicated H-alpha telescopes)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1047\" data-end=\"1122\"\u003e\n\u003cp data-start=\"1049\" data-end=\"1122\"\u003e\u003cstrong data-start=\"1049\" data-end=\"1070\"\u003eOptical Aperture:\u003c\/strong\u003e \u003cstrong data-start=\"1071\" data-end=\"1080\"\u003e40 mm\u003c\/strong\u003e (front-mounted; no central obstruction)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1123\" data-end=\"1181\"\u003e\n\u003cp data-start=\"1125\" data-end=\"1181\"\u003e\u003cstrong data-start=\"1125\" data-end=\"1166\"\u003eBandpass (effective, double-stacked):\u003c\/strong\u003e \u003cstrong data-start=\"1167\" data-end=\"1179\"\u003e~\u0026lt;0.50 Å\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1182\" data-end=\"1262\"\u003e\n\u003cp data-start=\"1184\" data-end=\"1262\"\u003e\u003cstrong data-start=\"1184\" data-end=\"1222\"\u003eBandpass (single-stack reference):\u003c\/strong\u003e \u003cstrong data-start=\"1223\" data-end=\"1234\"\u003e\u0026lt;0.70 Å\u003c\/strong\u003e (host system prior to DS)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1263\" data-end=\"1306\"\u003e\n\u003cp data-start=\"1265\" data-end=\"1306\"\u003e\u003cstrong data-start=\"1265\" data-end=\"1276\"\u003eTuning:\u003c\/strong\u003e \u003cstrong data-start=\"1277\" data-end=\"1285\"\u003eTilt\u003c\/strong\u003e (integrally tuned)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1307\" data-end=\"1361\"\u003e\n\u003cp data-start=\"1309\" data-end=\"1361\"\u003e\u003cstrong data-start=\"1309\" data-end=\"1348\"\u003eTelescope Focal Length (unchanged):\u003c\/strong\u003e \u003cstrong data-start=\"1349\" data-end=\"1359\"\u003e400 mm\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1362\" data-end=\"1397\"\u003e\n\u003cp data-start=\"1364\" data-end=\"1397\"\u003e\u003cstrong data-start=\"1364\" data-end=\"1375\"\u003eWeight:\u003c\/strong\u003e \u003cstrong data-start=\"1376\" data-end=\"1395\"\u003e~1 lb (~0.4 kg)\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1398\" data-end=\"1473\"\u003e\n\u003cp data-start=\"1400\" data-end=\"1473\"\u003e\u003cstrong data-start=\"1400\" data-end=\"1412\"\u003eStorage:\u003c\/strong\u003e Fits optional \u003cstrong data-start=\"1427\" data-end=\"1454\"\u003eLS40 aluminum hard case\u003c\/strong\u003e with fitted foam\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1474\" data-end=\"1567\"\u003e\n\u003cp data-start=\"1476\" data-end=\"1567\"\u003e\u003cstrong data-start=\"1476\" data-end=\"1499\"\u003eSafety Requirement:\u003c\/strong\u003e Use \u003cstrong data-start=\"1504\" data-end=\"1540\"\u003eonly with a Lunt Blocking Filter\u003c\/strong\u003e appropriate to your system\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch1 data-start=\"1569\" data-end=\"1589\"\u003eWhat’s in the Box?\u003c\/h1\u003e\n\u003cul data-start=\"1590\" data-end=\"1641\"\u003e\n\u003cli data-start=\"1590\" data-end=\"1641\"\u003e\n\u003cp data-start=\"1592\" data-end=\"1641\"\u003e\u003cstrong data-start=\"1592\" data-end=\"1639\"\u003eLunt LS40FHa 40 mm Double Stack Etalon Unit\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1643\" data-end=\"1809\" data-is-last-node=\"\" data-is-only-node=\"\"\u003e\u003cem data-start=\"1643\" data-end=\"1651\"\u003eNotes:\u003c\/em\u003e A \u003cstrong data-start=\"1654\" data-end=\"1683\"\u003eLunt Blocking Filter (BF)\u003c\/strong\u003e is required and sold separately. This DS filter is designed \u003cstrong data-start=\"1744\" data-end=\"1759\"\u003eexclusively\u003c\/strong\u003e for Lunt’s dedicated \u003cstrong data-start=\"1781\" data-end=\"1789\"\u003eLS40\u003c\/strong\u003e H-alpha telescopes.\u003c\/p\u003e","brand":"Lunt Solar Systems","offers":[{"title":"Default Title","offer_id":50952870986048,"sku":"LS40FHa","price":779.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0717\/9904\/6464\/files\/40ds-tres.png?v=1756160574","url":"https:\/\/astroworldtelescopes.com\/products\/lunt-40mm-double-stack-filter-for-ls40tha","provider":"Astroworld Telescopes","version":"1.0","type":"link"}