{"product_id":"3-0-79x-reducer-field-flattener-apo-refractor","title":"3\" 0.79x Reducer \u0026 Field Flattener for APO Refractors (APS-C Ready)","description":"\u003ch2\u003e3\" 0.79x Reducer \u0026amp; Field Flattener for APO Refractors\u003c\/h2\u003e\n\n\u003cp\u003e\nThe 3\" 0.79x reducer and field flattener is designed for astrophotography with high-quality APO refractor telescopes. \nIt reduces focal length by 0.79x while correcting field curvature, delivering sharp stars across the entire image – even with large APS-C sensors such as the ASI2600.\n\u003c\/p\u003e\n\n\u003cp\u003e\nThis reducer is ideal for refractors with focal lengths around 800–1000mm, making it a perfect match for 127mm class telescopes. \nIt provides a wider field of view, faster imaging, and improved edge-to-edge performance without requiring extreme backfocus distances.\n\u003c\/p\u003e\n\n\u003ch2\u003eAstrophotography Performance\u003c\/h2\u003e\n\n\u003cp\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/tsapo102s-ts-0.79x-photoline-reducer-jensen-1000x1000w.webp?v=1774280752\" alt=\"Crescent Nebula image using 0.79x reducer\"\u003e\n\u003c\/p\u003e\n\n\u003cp\u003e\nImage: Crescent Nebula by Johannes Jensen\u003cbr\u003e\nSetup used:\u003cbr\u003e\n♦ 102mm f\/7 APO refractor\u003cbr\u003e\n♦ 0.79x reducer\/flattener\u003cbr\u003e\n♦ DSLR camera – 36 x 360 second exposures\n\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003e0.79x focal reduction for wider field and faster imaging\u003c\/li\u003e\n\u003cli\u003eFlattens field curvature for pinpoint stars across the frame\u003c\/li\u003e\n\u003cli\u003eLarge 3\" optics – ideal for APS-C sensors (e.g. ASI2600)\u003c\/li\u003e\n\u003cli\u003eOptimised for refractors around 800–1000mm focal length\u003c\/li\u003e\n\u003cli\u003eNo extreme backfocus required\u003c\/li\u003e\n\u003cli\u003eImproves illumination and reduces edge distortion\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eBackfocus \u0026amp; Spacing\u003c\/h2\u003e\n\n\u003cp\u003e\nBackfocus distance is measured from the M48 thread to the camera sensor and depends on the telescope focal length:\n\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eUp to 350mm – 70mm\u003c\/li\u003e\n\u003cli\u003eUp to 420mm – 65mm\u003c\/li\u003e\n\u003cli\u003e450–500mm – 61mm\u003c\/li\u003e\n\u003cli\u003e510–600mm – 58mm\u003c\/li\u003e\n\u003cli\u003e610–700mm – 57mm\u003c\/li\u003e\n\u003cli\u003e710–790mm – 56mm\u003c\/li\u003e\n\u003cli\u003e800mm and above – 55mm\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\nFor most 127mm class refractors (~950mm focal length), the correct spacing is \u003cstrong\u003e55mm\u003c\/strong\u003e.\nSpacers and extension rings can be used to achieve precise backfocus.\n\u003c\/p\u003e\n\n\u003ch2\u003eCompatibility \u0026amp; Connection\u003c\/h2\u003e\n\n\u003cp\u003e\nThe reducer connects directly via an \u003cstrong\u003eM68 thread\u003c\/strong\u003e or can be inserted into a \u003cstrong\u003e3\" focuser\u003c\/strong\u003e. \nAdapters are available for compatibility with a wide range of telescope focusers.\n\u003c\/p\u003e\n\n\u003cp\u003e\nSuitable for:\n\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eAPO refractors with 2.5\" or larger focusers\u003c\/li\u003e\n\u003cli\u003e127mm class refractors (~900–1000mm focal length)\u003c\/li\u003e\n\u003cli\u003eAPS-C cameras such as ASI2600MC Pro\u003c\/li\u003e\n\u003cli\u003eDSLR and mirrorless astrophotography setups\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\nThis is a high-performance solution for astrophotographers looking for a wider field, faster imaging speed, and excellent edge correction.\n\u003c\/p\u003e","brand":"TS-Optics","offers":[{"title":"Default Title","offer_id":55509029290360,"sku":"TSRED379","price":348.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/photoline-0.79x-3-inch-reducer-flattener_2nd-1000x1000h_4933a89d-1730-44aa-b904-5abe7a4478e6.webp?v=1774281144","url":"https:\/\/www.darkclearskies.co.uk\/products\/3-0-79x-reducer-field-flattener-apo-refractor","provider":"Dark Clear Skies ","version":"1.0","type":"link"}