{"title":"Optec DSI Direct Screw Interface Adapters","description":"\u003cp\u003eOptec DSI Direct Screw Interface adapters use a large 3.5\" threaded connection to join Optec focusers and rotators to telescopes and cameras without set screws or compression rings. The line includes a 3.5\"x24tpi to M72x1 adapter for Takahashi telescopes, an OPTEC-4300 to DSI 3.5\" adapter and a five-piece 3.5\" extension tube set.\u003c\/p\u003e\u003cp\u003eA fully threaded train keeps heavy cameras rigid and square to the optical axis, which helps against tilt and flexure in long exposures.\u003c\/p\u003e","products":[{"product_id":"optec-optec-4300-to-dsi-3-5f-adapter","title":"Optec OPTEC-4300 to DSI 3.5\"(F) Adapter","description":"\u003c!-- more --\u003e\u003cp\u003e\u003cspan\u003eThe #19830 OPTEC-4300 to female Optec\/DSI 3.5\" threaded receiver allows any combination of our DSI 3.5-inch spacers to be easily installed on the camera side of the Gemini Focusing Rotator.\u003c\/span\u003e\u003c\/p\u003e\u003cdiv\u003e\u003cdiv id=\"tab-1\"\u003e\u003ctable width=\"100%\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eInside Diameter:\u003c\/td\u003e\n\u003ctd\u003e3.5\" DSI Thread\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutside Diameter:\u003c\/td\u003e\n\u003ctd\u003e4.95\" (125.7mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cp\u003eOverall Height:\u003c\/p\u003e\u003c\/td\u003e\n\u003ctd\u003e0.42\" (10.7mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture:\u003c\/td\u003e\n\u003ctd\u003e3.46\" (88mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight:\u003c\/td\u003e\n\u003ctd\u003e3.8 oz (110 g)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack-Focus Usage:\u003c\/td\u003e\n\u003ctd\u003e0.1\" (2.5mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\u003c\/div\u003e\u003cdiv\u003e\u003cp\u003e\u003cspan\u003eThe #19830 OPTEC-4300 to Optec\/DSI 3.5\" adapter converts the camera side receiver of the Gemini Focusing Rotator to a 3.5\" x 24tpi receiver for the Optec\/DSI 3.5\" spacers.  \u003c\/span\u003e\u003c\/p\u003e\u003c\/div\u003e","brand":"Optec","offers":[{"title":"Default Title","offer_id":44968071594269,"sku":"OPC-19830","price":189.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Optec-19830__79472.1674745738.1280.1280.png?v=1684348675"},{"product_id":"optec-dsi-3-5-extension-tube-set-5-pieces","title":"Optec DSI 3.5\" Extension Tube Set - 5 Pieces","description":"\u003c!-- more --\u003e\u003cp class=\"text-left\"\u003eRich Simons of \u003ca href=\"http:\/\/www.deepskyinstruments.com\/\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eDeep Sky Instruments\u003c\/a\u003e and \u003cstrong\u003eOptec\u003c\/strong\u003e have jointly developed a new, larger diameter standard spacer for large aperture telescopes.  Like the \u003ca href=\"https:\/\/optecinc.us\/collections\/astro-physics-2-7-adapters\"\u003eAstro-Physics 2.7-inch spacer set\u003c\/a\u003e, the Optec-DSI 3.5-inch spacers are available in a five different lengths.  \u003c\/p\u003e\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\u003cp class=\"text-left\"\u003eOptec-DSI 3.5-inch extension tubes feature female threads on one end with male threads on the opposite end with 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.  Click here for a table of the optimized spacer combinations. \u003c\/p\u003e\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\u003cul class=\"text-left\"\u003e\n\u003cli\u003eIncludes:  1\/2\", 3\/4\", 1\", 1-1\/2\", and 3\"\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","brand":"Optec","offers":[{"title":"Default Title","offer_id":44968074543389,"sku":"OPC-19890","price":350.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Optec-19890__39448.1674745982.1280.1280.jpg?v=1684348713"},{"product_id":"optec-dsi-3-5x24tpim-to-m72x1m-takahashi-adapter","title":"Optec DSI 3.5\"x24tpi(M) to M72x1(M) Takahashi Adapter","description":"\u003c!-- more --\u003e\u003cp\u003e\u003cspan\u003eOptec-DSI 3.5x24tpi male thread to M72x1mm (male) Takahashi thread.\u003c\/span\u003e\u003c\/p\u003e\u003cul class=\"text-left\"\u003e\n\u003cli\u003eOutside Diameter:  3.82\" (97.0mm)\u003c\/li\u003e\n\u003cli\u003eOverall Height: 0.74\" (18.8mm)\u003c\/li\u003e\n\u003cli\u003eClear Aperture: 2.56\"  (65.0mm)\u003c\/li\u003e\n\u003cli\u003eBack-focus Usage: 0.15\" (3.8mm)\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Optec","offers":[{"title":"Default Title","offer_id":44968074576157,"sku":"OPC-19917","price":133.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Optec-19917__34334.1674746159.1280.1280.jpg?v=1684348714"}],"url":"https:\/\/davidastro.com\/collections\/optec-dsi-direct-screw-interface-adapters.oembed","provider":"David Astro","version":"1.0","type":"link"}