{"product_id":"takahashi-epsilon-180ed-180mm-f-2-8-hyperbolic-flat-field-astrograph-ota","title":"Takahashi Epsilon 180ED 180mm f\/2.8 Hyperbolic Flat-Field Astrograph OTA","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Epsilon-180ED is Takahashi's largest and fastest Epsilon astrograph, a 180 mm hyperbolic Newtonian design running at a native f\/2.8. A hyperbolic primary mirror, flat secondary, and an integrated field-flattening corrector combine inside the tube to put a flat 44 mm image circle 56.2 mm behind the focuser, with no separate corrector to buy or align. The published tube weight is 10.7 kg, putting it toward the upper end of what a mid-to-large equatorial mount should carry with a full imaging train attached.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if your priority is imaging speed — f\/2.8 gathers light quickly enough to shorten exposure times noticeably against slower optics, which matters most for faint, extended nebulosity. It suits an imager already running a fast reflector or astrograph, since the larger 180 mm mirror and 10.7 kg tube ask for a mount with real payload margin and benefit from a user comfortable checking collimation.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHyperbolic primary + flat secondary + integrated flattener:\u003c\/strong\u003e corrects coma and field curvature inside the tube, with no separate corrector to purchase or space.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ef\/2.8 native speed:\u003c\/strong\u003e among the fastest astrograph designs Takahashi builds, cutting exposure times sharply against conventional reflectors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e44 mm image circle:\u003c\/strong\u003e covers full-frame and APS-C sensors with a flat field.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRack-and-pinion focuser with rotary framing and integrated Camera Angle Adjuster:\u003c\/strong\u003e rotates the imaging train to frame a target without loosening the tube rings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccessible collimation with reference marks on both mirrors:\u003c\/strong\u003e makes checking and adjusting the optical alignment more direct than on a typical Newtonian.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Epsilon-180ED combines a 180 mm hyperbolic primary with a flat secondary and a built-in multi-element field flattener — the same modified-hyperbolic-Newtonian family as the smaller Epsilon-160ED, scaled up to a larger primary and a faster f\/2.8. Takahashi's own comparison places this design's chromatic performance below that of a conventional Schmidt camera at the same speed, while keeping the focal plane flat without a curved plate or field corrector as a separate purchase. Back focus is fixed at 56.2 mm from the focuser's rear end. An optional Ɛ-EX 180ED extender changes the configuration to 780 mm at f\/4.3, holding the same 44 mm image circle and 56.2 mm back focus, for imagers who want a longer effective focal length on the same tube.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eFast deep-sky astrophotography of faint nebulae, galaxies and extended objects where exposure time matters; narrowband and broadband imaging with a cooled CMOS or CCD camera; observatory imaging setups built around a large, fast reflector.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe 56.2 mm back focus is fixed by the integrated flattener and measured from the rear of the focuser to the focal plane — camera body, filter wheel and any off-axis guider all need to fit within that figure together. The \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e covers this figure and the Ɛ-EX 180ED extender configuration, and we're glad to check a specific camera and filter setup against it before you order. As a Newtonian-derived design, the mirrors benefit from a collimation check after transport, and the built-in reference marks make that a more direct process than on many reflectors.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eNot built for eyepiece observing:\u003c\/strong\u003e the fast mirror and fixed-backfocus flattener are matched to a camera sensor.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eA larger mount than the Epsilon-160ED needs:\u003c\/strong\u003e at 10.7 kg published weight, this is a heavier tube than Takahashi's smaller Epsilon models and is worth checking against your mount's imaging payload rating, not just its rated visual capacity.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eMount and tripod are not included:\u003c\/strong\u003e this listing is the optical tube assembly only.\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\u003eThe flattener is built in, so there is no separate corrector to space out. Collimation is the part that takes practice on any fast Newtonian-derived design, and the reference marks on both mirrors here are built to make that check more direct.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eFast deep-sky astrophotography where exposure time and light-gathering speed matter more than reach — faint nebulae, galaxies and wide extended targets.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use it for visual observing?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIt has no real application in a visual eyepiece train; the flattener and back focus are set for a camera sensor.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat cameras does it fit?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eAny cooled CMOS or CCD astronomy camera reaching the 56.2 mm back focus with its own nosepiece, filter wheel or off-axis guider included in that figure — send us your camera and filter setup and we will work it out with you.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow is this different from the Epsilon-160ED?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe 180ED is larger and faster — 180 mm aperture at f\/2.8 against 160 mm at f\/3.3 — and correspondingly heavier at 10.7 kg against 6.9 kg.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 180 mm f\/2.8 hyperbolic astrograph with the flattener built in, delivering a flat 44 mm image circle at a fixed 56.2 mm back focus for imagers who want the fastest deep-sky speed Takahashi's Epsilon line offers.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047050498159,"sku":"TAK-TEK18010","price":6678.1,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/TEK18010_Epsilon-180ED_OTA_1.jpg?v=1786911699","url":"https:\/\/ontariotelescope.com\/products\/takahashi-epsilon-180ed-180mm-f-2-8-hyperbolic-flat-field-astrograph-ota","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}