{"product_id":"takahashi-fct-65d-0-65x-fu-reducer","title":"Takahashi FCT-65D 0.65x FU Reducer","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe FCT-65D 0.65x FU Reducer is Takahashi's dedicated fluorite focal reducer for the FCT-65D refractor. It brings the telescope's native 400mm f\/6.2 down to 260mm at f\/4.0, and two of its elements are fluorite glass — the material that lets Takahashi push a reduction this aggressive while still holding a flat Φ44mm image circle.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis reducer suits FCT-65D owners imaging wide star fields, nebulae, and comets who want the fastest focal ratio the telescope supports. At f\/4.0 it gathers roughly 2.4x the light of the native f\/6.2 setup for the same exposure time.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFluorite reducer elements:\u003c\/strong\u003e control the chromatic error a reduction this strong would otherwise introduce.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e0.65x reduction:\u003c\/strong\u003e takes the FCT-65D from 400mm f\/6.2 to 260mm f\/4.0.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eΦ44mm corrected image circle:\u003c\/strong\u003e covers a full APS-C sensor with sharp stars into the corners.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM55.9 thread mount:\u003c\/strong\u003e installs directly into the FCT-65D drawtube system.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe reducer sits mostly inside the FCT-65D's drawtube, so the aggressive 0.65x reduction adds little to the telescope's front-to-back balance. It pairs with the included CA-35 (FURD) spacing ring, which sets a fixed back focus of 56.0mm measured from the rear of the adapter rather than from the telescope's own focal plane — the figure to build your imaging train from. See the \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e for the full spacing chain.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eWide-field deep-sky imaging of nebulae, clusters, and large galaxies; comet photography where a fast focal ratio shortens the exposures needed on a moving target; general FCT-65D astrophotography where exposure time is at a premium.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eTelescope\u003c\/th\u003e\n\u003cth\u003eResulting focal length\u003c\/th\u003e\n\u003cth\u003eResulting focal ratio\u003c\/th\u003e\n\u003cth\u003eImage circle\u003c\/th\u003e\n\u003cth\u003eBack focus\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFCT-65D\u003c\/td\u003e\n\u003ctd\u003e260mm\u003c\/td\u003e\n\u003ctd\u003ef\/4.0\u003c\/td\u003e\n\u003ctd\u003eΦ44mm\u003c\/td\u003e\n\u003ctd\u003e56.0mm (from rear of adapter)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003cp\u003eThe CA-35 (FURD) spacing ring ships with the reducer and fixes the 56.0mm figure above. Camera-side spacing from there follows your camera's own flange distance — the \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e covers the full chain.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eBuilt specifically for the FCT-65D:\u003c\/strong\u003e the figures above are for that telescope only — other Takahashi refractors pair with their own dedicated reducers.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it threads into the FCT-65D drawtube along with the included CA-35 spacing ring, and the 56.0mm back focus figure is fixed by that ring rather than something you measure and adjust yourself.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eWide-field astrophotography on the FCT-65D, where the 0.65x reduction to f\/4.0 shortens exposures on nebulae, clusters, and comets.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work for visual observing?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it's built to deliver a flat photographic image circle rather than a visual, eyepiece-compatible path.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat else do I need with it?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe CA-35 (FURD) spacing ring, included with the reducer, and your camera's own T-ring or adapter to complete the 56.0mm back focus.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA dedicated fluorite reducer that takes the FCT-65D to 260mm at f\/4.0 with a flat Φ44mm image circle, set up with the included CA-35 ring at a fixed 56.0mm back focus.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047107907695,"sku":"TAK-TKA11580F","price":1086.8,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tka11580f.jpg?v=1786913880","url":"https:\/\/ontariotelescope.com\/products\/takahashi-fct-65d-0-65x-fu-reducer","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}