{"product_id":"optec-dsi-35-telescope-spacers","title":"Optec-DSI 3.5\" Telescope Spacers","description":"\u003ch2\u003eOptec-DSI 3.5\" Telescope Spacers\u003c\/h2\u003e\n\u003ch4 class=\"text-left\"\u003eHigh Performance 3.5″ Threaded Extension Rings\u003c\/h4\u003e\n\u003cp class=\"text-left\"\u003eRich Simons of Deep Sky Instruments and\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eOptec\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ehave jointly developed a new, larger diameter standard spacer for large aperture telescopes: the Optec-DSI 3.5″ Telescope Spacers.  Like the Astro-Physics 2.7-inch spacer set, the Optec-DSI 3.5″ Telescope Spacers are available in a five different lengths.\u003c\/p\u003e\n\u003cp class=\"text-left\"\u003eThe AP 2.7-inch thread has become an astronomy industry standard thanks to the tireless efforts of Roland and his team at Astro-Physics.  Optec has produced a complementary extension set and a few new adapters in an effort to extend this industry standard. However, there are times when the 2.5″ clear aperture of the AP2.7 spacers will not allow enough light through clipping the edge rays.\u003c\/p\u003e\n\u003cp\u003eOptec-DSI 3.5-inch extension tubes feature female threads on one end with male threads on the opposite end\u003cbr\u003ewith knurled bases to help attach and detach these tubes.  The extensions can be combined and stacked. We believe our four and five piece sets will provide all the needed extension for fixed focal length telescopes with 1\/4″ (6.35mm) increments using a minimum number of pieces.  See Manuals \u0026amp; Downloads tab for a table of the optimized spacer combinations.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp class=\"text-left\"\u003eAll extensions and mounts are made from high strength 6061 aluminum alloy and black anodized.  Anti-reflection threading and internal baffles on the largest extension tube help minimize internal reflections.  All internal surfaces are painted and baked with a non-reflecting ultra-flat black paint.\u003c\/p\u003e\n\u003cul class=\"text-left\"\u003e\n\u003cli\u003eSpacer Lengths Available: 1\/2″ (19891), 3\/4″ (19892), 1″ (19893), 1-1\/2″ (19894), and 3″ (19895)\u003c\/li\u003e\n\u003cli\u003eClear Aperture: 3.25″ (82.5mm)\u003c\/li\u003e\n\u003cli\u003eBack-focus Usage: Variable (see TABLE)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eAvailable Sets\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e4-Piece Set (19889)\u003c\/em\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eIncludes: 1\/2″, 3\/4″, 1″, and 1-1\/2″ spacers\u003c\/li\u003e\n\u003cli\u003ePossible spacer combinations:\u003cbr\u003e0.5″ through 3.25″ with 1\/4-inch increments plus 3.75″ with all spacers combined.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003e5-piece set (19890)\u003c\/strong\u003e\u003c\/em\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eIncludes:  1\/2″, 3\/4″, 1″, 1-1\/2″, and 3″ spacers\u003c\/li\u003e\n\u003cli\u003ePossible spacer combinations:\u003cbr\u003e0.5″ through 6.25″ with 1\/4-inch increments plus 6.75″ with all spacers combined.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 data-mce-fragment=\"1\"\u003eTechnical Specifications\u003cbr data-mce-fragment=\"1\"\u003e\n\u003c\/h3\u003e\n\u003cp\u003eDSI 3.5 Spacer Thread Specs\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDSI 3.5 Extension – 1\/2″ Length (19891)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOverall Height: 0.88″ (22.4mm)\u003cbr\u003eClear Aperture: 3.25″ (82.5mm)\u003cbr\u003eWeight: 1.0 oz. (30 g)\u003cbr\u003eBack-focus Usage: 0.50″ (12.7mm)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDSI 3.5 Extension – 3\/4″ Length (19892)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOverall Height: 1.13″ (28.7mm)\u003cbr\u003eClear Aperture: 3.25″ (82.5mm)\u003cbr\u003eWeight: 1.4 oz. (40 g)\u003cbr\u003eBack-focus Usage: 0.75″ (19.1mm)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDSI 3.5 Extension – 1″ Length (19893)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOverall Height: 1.38″ (35.0mm)\u003cbr\u003eClear Aperture: 3.25″ (82.5mm)\u003cbr\u003eWeight: 1.8 oz. (55 g)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDSI 3.5 Extension – 1-1\/2″ Length (19894)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOverall Height: 1.87″ (47.5mm)\u003cbr\u003eClear Aperture: 3.25″ (82.5mm)\u003cbr\u003eWeight: 2.4 oz. (70 g)\u003cbr\u003eBack-focus Usage: 1.50″ (38.1mm)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDSI 3.5 Extension – 3″ Length (19895)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOverall Height: 3.38″ (85.8mm)\u003cbr\u003eClear Aperture: 3.25″ (82.5mm)\u003cbr\u003eWeight: 8.2 oz. (230 g)\u003cbr\u003eBack-focus Usage: 3.00″ (76.2mm)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDSI 3.5 Retaining Ring (19897)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOverall Height: 0.14″ (3.5mm)\u003cbr\u003eClear Aperture: 3.45″ (87mm)\u003cbr\u003eWeight: 0.4 oz. (15 g)\u003cbr\u003eBack-focus Usage: 0.10″ (2.5mm)\u003cbr\u003eAnodize: Gold\u003c\/p\u003e\n\u003ch3 data-mce-fragment=\"1\"\u003eIn the Box\u003cbr data-mce-fragment=\"1\"\u003e\n\u003c\/h3\u003e\n\u003cp\u003eDepends on the choice.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e4-piece set (19889)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e3.5 Extension – 1\/2″ Length (19891)\u003cbr\u003e3.5 Extension – 3\/4″ (19892)\u003cbr\u003e3.5 Extension – 1″ Length (19893)\u003cbr\u003e3.5 Extension – 1-1\/2″ Length (19894)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e5-piece set (19890)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e3.5 Extension – 1\/2″ Length (19891)\u003cbr\u003e3.5 Extension – 3\/4″ (19892)\u003cbr\u003e3.5 Extension – 1″ Length (19893)\u003cbr\u003e3.5 Extension – 1-1\/2″ Length (19894)\u003cbr\u003e3.5 Extension – 3″ Length (19895)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e1\/2″ individual extension (19891)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e3.5 Extension – 1\/2″ Length (19891)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e3\/4″ individual extension (19892)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e3.5 Extension – 3\/4″ (19892)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e1″ individual extension (19893)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e3.5 Extension – 1″ Length (19893)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-1\/2″ individual extension (19894)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e3.5 Extension – 1-1\/2″ Length (19894)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e3″ individual extension (19895)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e3.5 Extension – 3″ Length (19895)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRetaining Ring (19897)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e3.5 Retaining Ring\u003c\/p\u003e\n\u003ch3 data-mce-fragment=\"1\"\u003eManual \u0026amp; Warranty\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eOfficina Stellare 1-Year Warranty\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eOptec-DSI Optimized Spacer Combinations\u003c\/p\u003e\n\u003cp\u003eDSI 3.5 Spacer Thread Specs\u003c\/p\u003e\n\u003ch3 class=\"text-left\"\u003e\u003cbr\u003e\u003c\/h3\u003e","brand":"Optec","offers":[{"title":"4 pieces set (19889)","offer_id":52326085427501,"sku":"xyi1787936689848","price":157.83,"currency_code":"USD","in_stock":true},{"title":"5 pieces set (19890)","offer_id":52326085460269,"sku":"owh1787936689849","price":184.64,"currency_code":"USD","in_stock":true},{"title":"1\/2\" Individual Extension (19891)","offer_id":52326085493037,"sku":"kan1787936689850","price":43.4,"currency_code":"USD","in_stock":true},{"title":"3\/4\" Individual Extension (19892)","offer_id":52326085525805,"sku":"qyi1787936689851","price":47.35,"currency_code":"USD","in_stock":true},{"title":"1\" Individual Extension (19893)","offer_id":52326085558573,"sku":"xvi1787936689852","price":48.66,"currency_code":"USD","in_stock":true},{"title":"1-1\/2\" Individual Extension (19894)","offer_id":52326085591341,"sku":"dau1787936689853","price":48.66,"currency_code":"USD","in_stock":true},{"title":"3\" Individual Extension (19895)","offer_id":52326085624109,"sku":"fuj1787936689854","price":63.64,"currency_code":"USD","in_stock":true},{"title":"Retaining Ring (19897)","offer_id":52326085656877,"sku":"dqd1787936689855","price":19.73,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0924\/0749\/7005\/files\/optec-dsi-35-telescope-spacers_1.jpg?v=1787936694","url":"https:\/\/www.camomileridge.shop\/products\/optec-dsi-35-telescope-spacers","provider":"My Store","version":"1.0","type":"link"}