{"product_id":"takahashi-foa-60-0-93x-flattener","title":"Takahashi FOA-60 0.93x Flattener","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe FOA-60 0.93x Flattener is the field corrector built specifically for Takahashi's FOA-60 Ortho Apochromat. Threaded to the FOA-60's 2-inch drawtube and finishing in an M52 x 0.75 female output, it brings the focal length from 530 mm down to 495 mm at f\/8.2 while flattening the field to within 10 microns across a 44 mm image circle. It weighs 205 g and adds 67 mm of length ahead of the sensor.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you already own the FOA-60 and want a flat, coma-free field for imaging — small-sensor deep-sky work, lunar mosaics, or solar eclipse photography where the corner stars matter as much as the center.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePurpose-built for the FOA-60:\u003c\/strong\u003e not a universal flattener — matched specifically to this 60mm ortho-apochromat's native curvature.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e44mm corrected image circle:\u003c\/strong\u003e covers full-frame sensors with the field flattened to within roughly 10 microns.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e495mm f\/8.2 result:\u003c\/strong\u003e a modest 0.93x reduction that trims the native 530mm f\/8.8 slightly while correcting the field.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompact in-line design:\u003c\/strong\u003e 56mm diameter, 67mm long, 205g, threading directly between the 2-inch drawtube and an M52 x 0.75 camera train.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe corrector uses two lens elements in two groups to cancel the FOA-60's residual field curvature, the tradeoff Takahashi's ortho-apochromat design makes for its high on-axis Strehl ratio. The output back focus works out to 56.0 mm from the flattener, so spacing to the sensor is a fixed rather than adjustable figure once the M52 x 0.75 thread is engaged.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eDeep-sky imaging where corner star shape matters, lunar mosaic photography, and solar eclipse imaging with a full-frame or APS-C sensor.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis flattener is matched to the FOA-60 only — the table below is Takahashi's published figure for that pairing.\u003c\/p\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eTelescope\u003c\/th\u003e\n\u003cth\u003eNative\u003c\/th\u003e\n\u003cth\u003eWith FL 0.93x\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\u003eFOA-60\u003c\/td\u003e\n\u003ctd\u003e530mm f\/8.8\u003c\/td\u003e\n\u003ctd\u003e495mm f\/8.2\u003c\/td\u003e\n\u003ctd\u003eΦ44mm\u003c\/td\u003e\n\u003ctd\u003e56.0mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/TKA28582_FOA-60_FL093x_schema.png?v=1786913972\" alt=\"Dimensional diagram of the Takahashi FOA-60 0.93x Flattener\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003cp\u003eBackfocus and thread spacing for the whole FOA-60 imaging train are covered in the \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eNot combined with the FOA-60Q 1.7x extender:\u003c\/strong\u003e the flattener and the EX 1.7xR extender serve different configurations of the same tube and are not used together.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eBuilt for imaging, not eyepiece use:\u003c\/strong\u003e the flattened field has no benefit for visual observing, where the FOA-60's native curvature is not a factor.\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 onto the FOA-60's 2-inch drawtube on one side and presents an M52 x 0.75 female thread on the camera side, so the spacing is fixed by the part itself rather than something to measure out.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eFlat-field imaging on the FOA-60 — deep-sky, lunar, and solar eclipse photography.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work on other Takahashi refractors?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — it is matched to the FOA-60's specific curvature. Other Takahashi models use their own matched flatteners; if you are unsure which one applies to your scope, send us your setup and we will confirm it.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it change the FOA-60 into the FOA-60Q?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo — that conversion uses the separate EX 1.7xR extender, which is not used together with this flattener.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe FOA-60 0.93x Flattener is the matched corrector for Takahashi's FOA-60, turning it into a 495mm f\/8.2 system with a flat 44mm image circle for imaging, at 205 g and a fixed 56.0mm back focus.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047112724591,"sku":"TAK-TKA28582","price":476.19,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/TKA28582_FOA-60_flattener_1.jpg?v=1786914111","url":"https:\/\/ontariotelescope.com\/products\/takahashi-foa-60-0-93x-flattener","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}