{"product_id":"takahashi-fc-76d-reducer","title":"Takahashi FC-76D Reducer","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eTakahashi's dedicated reducer for the FC-76D, and compatible with all FC-76 and FS-78 tubes. On the FC-76D it produces 417 mm at f\/5.5 with a 36 mm image circle — a faster, wider system than the telescope's native configuration, with enough illuminated field to cover an APS-C sensor comfortably.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you image with an FC-76D, FC-76 or FS-78 and want a faster focal ratio and a wider field.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e417 mm at f\/5.5 on the FC-76D:\u003c\/strong\u003e the headline configuration this reducer was designed around.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e36 mm image circle:\u003c\/strong\u003e consistent across all three compatible telescopes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDedicated design:\u003c\/strong\u003e built for the FC-76D specifically rather than adapted from a general-purpose corrector.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlso fits FC-76 and FS-78:\u003c\/strong\u003e each with its own resulting focal length and ratio.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA reducer shortens effective focal length and speeds the focal ratio, which shortens exposures and widens the field — but only holds up if the corners stay sharp. Takahashi publishes a 36 mm image circle for this reducer on all three compatible tubes, which covers an APS-C sensor (roughly 28 mm diagonal) with real margin, and reaches most of a full-frame sensor's 43 mm diagonal without covering its corners. The three telescopes each land at a slightly different focal length behind it — 417 mm on the FC-76D, 438 mm on the FC-76, 462 mm on the FS-78 — because each starts from a different native focal length.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eWide-field deep-sky imaging on a small Takahashi refractor: large nebulae, star fields, and widefield framing where the native focal ratio would ask for longer exposures.\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\u003eFocal length with reducer\u003c\/th\u003e\n\u003cth\u003eFocal ratio\u003c\/th\u003e\n\u003cth\u003eImage circle\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFC-76D\u003c\/td\u003e\n\u003ctd\u003e417mm\u003c\/td\u003e\n\u003ctd\u003ef\/5.5\u003c\/td\u003e\n\u003ctd\u003e36mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFC-76\u003c\/td\u003e\n\u003ctd\u003e438mm\u003c\/td\u003e\n\u003ctd\u003ef\/5.8\u003c\/td\u003e\n\u003ctd\u003e36mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFS-78\u003c\/td\u003e\n\u003ctd\u003e462mm\u003c\/td\u003e\n\u003ctd\u003ef\/5.9\u003c\/td\u003e\n\u003ctd\u003e36mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003cp\u003eTakahashi does not publish the backfocus figure on this listing, and that is the number that decides corner star shape once your camera and filters are in the train. Send us the camera and any filter drawer or spacers you are running and we will work the total through with you before you order.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eAn imaging corrector, not a visual one:\u003c\/strong\u003e it is designed for a camera at the focal plane and has no application in a visual train with an eyepiece.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003e36 mm image circle:\u003c\/strong\u003e that covers APS-C with margin. A full-frame sensor's corners fall outside it, so full-frame users should expect fall-off at the extremes.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eBackfocus is not published here:\u003c\/strong\u003e it is the figure worth pinning down for your exact camera, and we will do that with you.\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 train. The work is in getting the spacing to the sensor right, and that is a number we can give you for your setup.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does it do to my focal length?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e417 mm at f\/5.5 on the FC-76D, 438 mm at f\/5.8 on the FC-76, 462 mm at f\/5.9 on the FS-78.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill it cover my camera?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe 36 mm image circle covers APS-C comfortably. Full-frame corners sit outside it.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich telescopes does it fit?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe FC-76D, all FC-76 tubes, and the FS-78.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA dedicated reducer that takes the FC-76D to 417 mm at f\/5.5 over a 36 mm field — a faster, wider version of a small Takahashi refractor for imaging.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54086044516463,"sku":"TAK-TKA18580","price":875.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/tka1858_1_2_6.jpg?v=1787328881","url":"https:\/\/ontariotelescope.com\/products\/takahashi-fc-76d-reducer","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}