{"product_id":"sky-watcher-esprit-70edx-evostar-100edx-flattener","title":"Sky-Watcher Esprit 70EDX \/ Evostar 100EDX Flattener","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e0.92x Reducer\/Flattener\u003c\/li\u003e\n\u003cli\u003eCompatible with the Esprit 70EDX and Evostar 100EDX\u003c\/li\u003e\n\u003cli\u003e44mm Image Circle for Full-Frame Sensors\u003c\/li\u003e\n\u003cli\u003eEsprit 70EDX: 490mm f\/7 to 450mm f\/6.4\u003c\/li\u003e\n\u003cli\u003eEvostar 100EDX: 700mm f\/7 to 644mm f\/6.4\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\u003eSky-Watcher Esprit 70EDX \/ Evostar 100EDX Flattener\u003c\/h2\u003e\n\u003cp\u003eThe Sky-Watcher Esprit 70EDX \/ Evostar 100EDX Flattener is a 0.92x reducer\/flattener that corrects the natural field curvature of both telescopes and delivers a flat field across a 44mm image circle. It also slightly shortens the focal length, bringing both scopes from f\/7 to f\/6.4 for faster imaging.\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\u003e44mm Flat Field for Full-Frame Sensors\u003c\/h3\u003e\n\u003cp\u003eWithout a flattener, stars at the edges of a large sensor turn into elongated shapes because a refractor's focal plane is curved. This flattener corrects that curvature across a 44mm image circle, wide enough to cover the diagonal of a full-frame sensor, so stars stay point-like from the center to the corners.\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\u003e0.92x Reduction: f\/7 to f\/6.4\u003c\/h3\u003e\n\u003cp\u003eThe 0.92x reduction speeds both telescopes from f\/7 to f\/6.4, which shortens the exposure time needed for the same signal by about 15% and slightly widens the field of view.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eEsprit 70EDX:\u003c\/strong\u003e 490mm at f\/7 becomes 450mm at f\/6.4.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEvostar 100EDX:\u003c\/strong\u003e 700mm at f\/7 becomes 644mm at f\/6.4.\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\"\u003eWhich telescopes does this flattener fit?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eSky-Watcher lists it for two telescopes: the Esprit 70EDX Super APO Triplet and the Evostar 100EDX APO Doublet. For the Esprit 100EDX, use the dedicated Esprit 100EDX Flattener (S20217).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill it cover a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The 44mm image circle is larger than the roughly 43mm diagonal of a full-frame sensor, and it covers APS-C and smaller sensors with room to spare.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes it reduce the focal length?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, slightly. It is a 0.92x reducer\/flattener, so the Esprit 70EDX goes from 490mm to 450mm and the Evostar 100EDX from 700mm to 644mm, both at f\/6.4.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat back focus does the flattener need?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eSky-Watcher had not published the back focus specification for this flattener at launch. Contact us before ordering and we will confirm the correct sensor spacing for your camera.\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\u003eUPC\u003c\/td\u003e\n\u003ctd\u003e810098970754\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eOptical Specifications\u003c\/strong\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eReducer\/Field Flattener\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction\u003c\/td\u003e\n\u003ctd\u003e0.92x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eCompatibility\u003c\/strong\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescopes\u003c\/td\u003e\n\u003ctd\u003eEsprit 70EDX, Evostar 100EDX\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEsprit 70EDX with Flattener\u003c\/td\u003e\n\u003ctd\u003e450mm at f\/6.4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEvostar 100EDX with Flattener\u003c\/td\u003e\n\u003ctd\u003e644mm at f\/6.4\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\"\u003eEsprit 70EDX \/ Evostar 100EDX Flattener\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\u003ca href=\"https:\/\/davidastro.com\/pages\/sky-watcher-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eSky-Watcher 2-Year Limited Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":67666300436765,"sku":"SW-S20216","price":310.0,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/100_2_c036ec1b-e071-4037-9437-5adb55294a87.jpg?v=1790967073","url":"https:\/\/davidastro.com\/products\/sky-watcher-esprit-70edx-evostar-100edx-flattener","provider":"David Astro","version":"1.0","type":"link"}