{"product_id":"takahashi-foa-60-60mm-f-8-8-ortho-apochromatic-refractor-ota","title":"Takahashi FOA-60 60mm f\/8.8 Ortho Apochromatic Refractor OTA","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe FOA-60 is Takahashi's Ortho Apochromat — a 60 mm fluorite doublet built for correction quality rather than field width, with a published Strehl ratio in excess of 96%, a figure normally associated with Takahashi's larger TOA series. At 530 mm focal length and f\/8.8 it is a slower, more deliberate design than the FS-60 line, in a retractable-dew-shield tube that weighs 1.8 kg.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if what you want from a 60 mm refractor is correction quality — tight, well-controlled stars for lunar and planetary detail and demanding double-star splits — rather than the widest possible field. It suits observers and imagers who already own a wide-field instrument and want a second, high-precision tube for close work, and anyone who wants a compact travel scope that performs like a considerably larger apochromat on the moon and planets.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrtho Apochromat design:\u003c\/strong\u003e a two-element air-spaced fluorite doublet optimized for correction over field width — a published Strehl ratio above 96%.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e530 mm at f\/8.8:\u003c\/strong\u003e 60 mm aperture in a compact 500 mm tube.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e175.5 mm of back focus:\u003c\/strong\u003e ample working distance for a diagonal or camera train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRetractable dew shield:\u003c\/strong\u003e extends to 80 mm over a slim 68 mm tube for transport.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e84 mm drawtube extension\u003c\/strong\u003e on a rack-and-pinion focuser.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUpgrade path:\u003c\/strong\u003e the 1.7x EX extender converts it to the FOA-60Q configuration — 900 mm at f\/15 with a 44 mm image circle.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe FOA-60 uses the same two-element, air-spaced fluorite doublet family as the rest of the FS\/FC line, but Takahashi has specified and figured it as an Ortho Apochromat — a design tier aimed at the correction levels normally reserved for the TOA triplets. The published Strehl ratio, in excess of 96% at prime focus and over 99% with the 1.7x extender fitted, describes how closely the wavefront approaches a theoretically perfect optic; in practice it shows up as tighter Airy disks and cleaner diffraction rings on planets and double stars than a standard doublet at this aperture delivers.\u003c\/p\u003e\u003cp\u003eHard multicoatings protect the fluorite element, and the 175.5 mm of back focus — generous for a 60 mm scope — is what leaves room for the FL 0.93x flattener or the EX 1.7xR extender to reach focus without running out of drawtube travel.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLunar and planetary observing:\u003c\/strong\u003e at 530 mm and f\/8.8, or extended to 900 mm and f\/15 with the EX 1.7xR extender.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDouble-star splitting:\u003c\/strong\u003e the high Strehl ratio is most visible on close, even-magnitude pairs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompact travel observing:\u003c\/strong\u003e a 500 mm tube and 1.8 kg weight that packs down with the retractable dew shield.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlat-field imaging:\u003c\/strong\u003e with the FL 0.93x flattener, 495 mm at f\/8.2 across a 44 mm circle.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-resolution planetary imaging:\u003c\/strong\u003e with the EX 1.7xR extender, 900 mm at f\/15 across an 88 mm circle — the FOA-60Q configuration.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe FOA-60's system chart and extender chart, both in the Downloads tab, list the exact adapters and distances for the flattener and extender configurations. Our \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e collects the same figures for the whole Takahashi range.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBack focus:\u003c\/strong\u003e 175.5 mm at prime focus.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eField flattener:\u003c\/strong\u003e FL 0.93x — 495 mm, f\/8.2, 44 mm circle, 56.0 mm back focus.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtender:\u003c\/strong\u003e EX 1.7xR — converts the tube to the FOA-60Q configuration, 900 mm, f\/15, 88 mm circle, 208.1 mm back focus. The extender has its own system chart, included below.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMount:\u003c\/strong\u003e sold as an OTA — no mount, rings or dovetail included. At 1.8 kg it suits small to mid-sized equatorial and travel mounts.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eIf you already own the EX 1.7xR extender or are considering it, send us your camera and filter setup and we will confirm the back focus with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis is an optical tube assembly.\u003c\/strong\u003e Mount, tripod, rings, dovetail, diagonal, eyepiece and finder are sold separately.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA flat field for imaging needs the FL 0.93x flattener.\u003c\/strong\u003e At prime focus the field curves, as on any doublet refractor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e60 mm still sets the light grasp.\u003c\/strong\u003e The Ortho design improves correction, not aperture — its strength is image quality on bright, small targets rather than reach on faint deep-sky objects.\u003c\/li\u003e\n\u003c\/ul\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 — at prime focus it is a diagonal and eyepiece and you are observing. The flattener and extender configurations are documented on Takahashi's system charts in the Downloads tab, which list the parts and distances.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eLunar and planetary observing, double-star splitting, and high-resolution imaging once extended to the FOA-60Q configuration.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does Ortho Apochromat mean, and how is this different from the FS-60CB?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIt is a correction-focused design tier — a published Strehl ratio above 96% versus a standard doublet's typical figures — aimed at planetary and double-star performance rather than the FS-60CB's wide-field flexibility.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan this become a FOA-60Q?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes — fitting the EX 1.7xR extender converts it to the FOA-60Q's 900 mm f\/15 configuration with an 88 mm image circle.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it need a flattener for astrophotography?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eFor a flat field to the edge of frame, yes — the FL 0.93x flattener corrects the native field curvature.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 60 mm fluorite Ortho Apochromat at 530 mm and f\/8.8, with a Strehl ratio above 96%, 175.5 mm of back focus, and an upgrade path to 900 mm f\/15 with the EX 1.7xR extender.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047053545583,"sku":"TAK-TFA06010","price":1816.1,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/TFA06010_FOA-60_OTA_1.jpg?v=1786911866","url":"https:\/\/ontariotelescope.com\/products\/takahashi-foa-60-60mm-f-8-8-ortho-apochromatic-refractor-ota","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}