{"product_id":"takahashi-epsilon-e-160ed-160mm-f-3-3-hyperbolic-astrograph-ota","title":"Takahashi Epsilon E-160ED 160mm f\/3.3 Hyperbolic Astrograph OTA","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Epsilon-160ED is a 160 mm hyperbolic Newtonian astrograph from Takahashi, built for deep-sky imaging at a native f\/3.3. A hyperbolic primary mirror, flat secondary, and an integrated field-flattening corrector work together inside the tube, so there is no separate flattener to buy, align, or space out. The 530 mm focal length puts a flat 44 mm image circle 56.2 mm behind the focuser, and the published tube weight of 6.9 kg keeps it well inside the payload of a mid-size equatorial mount carrying a full imaging train.\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 deep-sky targets — nebulae, galaxies, and star clusters — and want the light-gathering speed of f\/3.3 without the curved focal plane and flat-field-adapter fuss of a Schmidt camera design. It suits an imager already comfortable with reflector collimation, since a Newtonian-derived optical path benefits from periodic checking. It is not built for eyepiece observing — the fast mirror and integrated flattener are optimized for a sensor at a fixed backfocus, not a diagonal and eyepiece.\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 lens to purchase or space.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ef\/3.3 native speed:\u003c\/strong\u003e a 530 mm focal length gathers light quickly, shortening exposure times for faint targets compared with a conventional f\/6–f\/8 reflector.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e44 mm image circle:\u003c\/strong\u003e covers full-frame and APS-C sensors, with the design holding spot size under roughly 3 micrometers at the field edge.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOversized rack-and-pinion focuser with integrated Camera Angle Adjuster:\u003c\/strong\u003e lets you rotate the imaging train to frame a target without loosening the tube rings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemovable central mirror cover:\u003c\/strong\u003e exposes the primary to ambient air for faster thermal acclimation before a session.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOpen spider-vane secondary support:\u003c\/strong\u003e reduces scattered light and diffraction spikes around bright stars.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eOptical \/ Mechanical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe Epsilon-160ED's optical path combines a 160 mm hyperbolic primary mirror with a flat secondary and a built-in multi-element field flattener, a configuration Takahashi calls a modified hyperbolic Newtonian. Unlike a Schmidt camera, the focal plane is flat and the corrective elements live inside the tube rather than as a separate accessory train, which keeps the back focus fixed at 56.2 mm from the focuser's rear end. At f\/3.3 the design cuts exposure times sharply against slower reflectors while holding the 44 mm image circle flat and coma-free. An optional Ɛ-EX 160ED extender changes the configuration to 800 mm at f\/5.0, with the same 44 mm image circle and 56.2 mm back focus, for imagers who want tighter framing on the same optical tube.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eWide- to moderate-field deep-sky astrophotography of nebulae, galaxies and star clusters; narrowband and broadband imaging with a cooled CMOS or CCD camera; observatory or portable imaging rigs built around a fast reflector rather than a refractor.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe 56.2 mm back focus is measured from the rear end of the focuser to the focal plane and is fixed by the integrated flattener — there is no field-flattener spacing to calculate for prime focus imaging. Camera trains, filter drawers and off-axis guiders all need to fit inside that figure, so it is worth checking your full imaging stack against it before ordering. The \u003ca href=\"\/pages\/takahashi-back-focus-guide\"\u003eTakahashi Back Focus Guide\u003c\/a\u003e covers this and the Ɛ-EX 160ED extender configuration in detail. Because this is a Newtonian-derived design, periodic collimation is part of ownership — Takahashi's collimating tools work with this tube.\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, not a diagonal and eyepiece.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCollimation is periodic maintenance, not a one-time setup:\u003c\/strong\u003e like any fast Newtonian-derived optic, the mirrors benefit from a collimation check after transport, and Takahashi's own collimating eyepiece and telescope handle it directly.\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 optical side is straightforward — the flattener is built in, so there is no separate corrector to space out. The part that takes practice is collimation, which any fast Newtonian-derived design needs checked periodically; Takahashi's collimating tools are built for this tube.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is it best used for?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eDeep-sky astrophotography at a fast focal ratio — nebulae, galaxies and clusters that benefit from short sub-exposures at f\/3.3.\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 that can reach 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-180ED?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe 180ED steps up to a 180 mm aperture and a faster f\/2.8, with a larger, heavier tube; the 160ED is the lighter, more mount-friendly option at f\/3.3.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 160 mm f\/3.3 hyperbolic astrograph with the flattener built in, delivering a flat 44 mm image circle at a fixed 56.2 mm back focus for fast deep-sky imaging.\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":54047049285743,"sku":"TAK-TEK16010","price":5648.5,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/TEK16010_1.jpg?v=1786911556","url":"https:\/\/ontariotelescope.com\/products\/takahashi-epsilon-e-160ed-160mm-f-3-3-hyperbolic-astrograph-ota","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}