{"product_id":"starizona-sct-corrector-iv-0-63x-reducer-coma-corrector","title":"Starizona SCT Corrector IV - 0.63x Reducer \/ Coma Corrector","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces focal ratio by a factor of 0.63x, making your telescope 2.5x faster\u003c\/li\u003e\n\u003cli\u003eCorrects for off-axis coma inherent in Schmidt-Cassegrain designs\u003c\/li\u003e\n\u003cli\u003eProvides a 27 mm image circle, accommodating most popular astronomy cameras and DSLRs\u003c\/li\u003e\n\u003cli\u003e5-element optical design with extra-low dispersion (ED) glass\u003c\/li\u003e\n\u003cli\u003eRequires a precise mechanical backfocus of 90.3 mm from the corrector's threads\u003c\/li\u003e\n\u003cli\u003eConnects to the telescope via a 2\" barrel and to the camera with M42 T-threads\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eStarizona SCT Corrector IV - 0.63x Reducer \/ Coma Corrector\u003c\/h2\u003e\n\u003cp\u003eThe Starizona SCT Corrector IV transforms a standard f\/10 Schmidt-Cassegrain into a corrected, wide-field astrograph by reducing the focal ratio by 0.63x and making the system 2.5x faster. Its 5-element optical design incorporates ED glass to correct off-axis coma across a 27 mm image circle. By converting a C11 to f\/6.3 or a C8 to f\/7.1, this corrector dramatically shortens exposure times while capturing a much wider field of view.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA 0.63x Reducer for a 2.5x Faster System\u003c\/h3\u003e\n\u003cp\u003eBy reducing your telescope's focal length by a factor of 0.63x, the SCT Corrector IV makes your imaging setup 2.5x faster than its native f\/10 configuration. This speed increase means you can capture the same amount of signal in less than half the time. For example, a Celestron C11 becomes a 1760 mm f\/6.3 instrument, and a C9.25 operates at 1525 mm f\/6.5.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA 5-Element ED Design for Coma-Free Fields\u003c\/h3\u003e\n\u003cp\u003eThe Starizona SCT Corrector IV is both a focal reducer and a coma corrector. Its 5-element optical path, which includes extra-low dispersion (ED) glass, is specifically engineered to counteract the inherent off-axis coma of SCT optical systems. Starizona's spot diagram for a Celestron 11\" SCT shows much smaller off-axis star images than the native telescope, and performance is similar on other sizes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eAchieving 90.3mm Backfocus for Optimal Correction\u003c\/h3\u003e\n\u003cp\u003eTo deliver its specified correction, the SCT Corrector IV requires a precise mechanical backfocus of 90.3 mm, measured from the base of its M42 camera-side threads to your sensor plane. For the best results, this distance must be maintained within a tolerance of +\/-2 mm. The corrector includes a 35.3 mm M42 spacer which, when attached, leaves a standard 55 mm backfocus, suitable for a DSLR with a T-ring or ZWO cooled cameras with their stock adapters. The telescope side features a 2\" barrel with 48 mm filter threads, allowing it to slide into any standard 2\" focuser or visual back.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSCT Corrector IV vs. the Original SCT Corrector\u003c\/h3\u003e\n\u003cp\u003eThe SCT Corrector IV is the current version of Starizona's SCT Corrector, combining a 0.63x reducer and a coma corrector in one 2\" barrel unit.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpeed:\u003c\/strong\u003e It is 1.4x faster than the original f\/7.5 SCT Corrector design.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptics:\u003c\/strong\u003e A 5-element design with extra-low dispersion (ED) glass and fully multi-coated optics.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLarger Sensors:\u003c\/strong\u003e For full-frame cameras on a C11 or C14, Starizona offers the SCT Corrector LF with a 42 mm image circle.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the Starizona SCT Corrector IV do?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt reduces the focal ratio of a standard SCT by 0.63x, making the system 2.5x faster than the native f\/10, and corrects off-axis coma. Its 5-element design uses extra-low dispersion (ED) glass and covers a 27 mm image circle.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I get the correct 90.3 mm spacing for the SCT Corrector IV?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 90.3 mm distance is measured from the shoulder of the M42 T-threads on the corrector to your camera's sensor. The corrector includes a 35.3 mm spacer adapter. When this is attached, you are left with a standard 55 mm backfocus requirement, which is common for DSLRs with a T-ring or ZWO cooled cameras with their stock adapters. You may need additional M42 spacers to achieve the correct distance for your specific imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Starizona SCT Corrector IV work with my 8\" f\/10 Meade SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. Starizona states it works great on standard f\/10 Meade SCTs, although it publishes nominal focal lengths only for Celestron models (for example 1450 mm at f\/7.1 on a C8).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat focal length and focal ratio does the SCT Corrector IV give on a C11?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOn a Celestron C11 it reduces the native 2800 mm focal length to a nominal 1760 mm at f\/6.3, for a wider field of view and a system 2.5x faster than f\/10. The exact focal length depends slightly on where the corrector sits in the optical path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhich cameras does the 27 mm image circle of the SCT Corrector IV cover?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 27 mm image circle accommodates most popular astronomy cameras and DSLRs. For the largest compatible cameras, keep the 90.3 mm backfocus within +\/-2 mm. For full-frame sensors on a C11 or C14, Starizona offers the SCT Corrector LF.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use filters with the Starizona SCT Corrector IV?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The front (telescope side) of the corrector is threaded for standard 2\" (48 mm) filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e5 elements with extra-low dispersion (ED) glass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.63x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImaging Speed\u003c\/td\u003e\n\u003ctd\u003e2.5x faster than native f\/10\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Image Circle\u003c\/td\u003e\n\u003ctd\u003e27 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMechanical Backfocus\u003c\/td\u003e\n\u003ctd\u003e90.3 mm (3.56\") from M42 thread shoulder\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackfocus w\/ Adapter\u003c\/td\u003e\n\u003ctd\u003e55 mm (with included 35.3 mm spacer)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTelescope Connection\u003c\/td\u003e\n\u003ctd\u003e2\" barrel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Connection\u003c\/td\u003e\n\u003ctd\u003eM42 x 0.75 mm (T-thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Threads\u003c\/td\u003e\n\u003ctd\u003e48 mm (for 2\" filters) on telescope side\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting f\/ratio (C6)\u003c\/td\u003e\n\u003ctd\u003ef\/8 (1220 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting f\/ratio (C8)\u003c\/td\u003e\n\u003ctd\u003ef\/7.1 (1450 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting f\/ratio (C9.25)\u003c\/td\u003e\n\u003ctd\u003ef\/6.5 (1525 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting f\/ratio (C11)\u003c\/td\u003e\n\u003ctd\u003ef\/6.3 (1760 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting f\/ratio (C14)\u003c\/td\u003e\n\u003ctd\u003ef\/6.7 (2365 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescopes\u003c\/td\u003e\n\u003ctd\u003eStandard f\/10 Celestron and Meade SCTs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eFully multi-coated optics\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHousing\u003c\/td\u003e\n\u003ctd\u003eBlack anodized, machined aluminum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Diameter\u003c\/td\u003e\n\u003ctd\u003e2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLength\u003c\/td\u003e\n\u003ctd\u003e2.5\" (excluding threads)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e270 g (0.6 lb)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eSCT Corrector IV 0.63x Reducer \/ Coma Corrector\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e35.3 mm Spacer Adapter (M42)\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/starizona-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eStarizona Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Starizona","offers":[{"title":"Default Title","offer_id":68022994895133,"sku":"STZ-SCTCORR-4","price":559.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/starizona-sct-corrector-iv-1.jpg?v=1794261422","url":"https:\/\/davidastro.com\/products\/starizona-sct-corrector-iv-0-63x-reducer-coma-corrector","provider":"David Astro","version":"1.0","type":"link"}