Takahashi Epsilon-180ED — 180 mm f/2.8 hyperbolic flat-field astrograph The Epsilon-180ED is the fastest of Takahashi's Epsilon astrographs. A 180 mm hyperbolic primary and an integrated corrector deliver 500 mm at f/2.8 with a flat 44 mm image circle, which makes it a short-exposure, wide-field workhorse for nebulae and star fields.
Manufacturer model: Takahashi Epsilon-180ED · Specifications checked against manufacturer data on 2026-11-03
Takahashi Epsilon-180ED — 180 mm f/2.8 hyperbolic flat-field astrograph
The Epsilon-180ED is the fastest of Takahashi's Epsilon astrographs. A 180 mm hyperbolic primary and an integrated corrector deliver 500 mm at f/2.8 with a flat 44 mm image circle, which makes it a short-exposure, wide-field workhorse for nebulae and star fields.
The Epsilon optical system
As in all Epsilon models, the hyperbolic primary corrects spherical aberration and coma, and a corrector integrated in the rack-and-pinion focuser flattens the field. Takahashi states that star images stay under 10 µm to the edge of the 44 mm image circle.
Built for imaging
The 500 mm focal length gives a field of view of about 5°. The secondary mirror is held by a reinforced spider to avoid flexure. The focuser includes a Camera Angle Adjuster (CAA), so you can rotate the camera to frame your target. With the optional Epsilon Extender 1.5×, the system becomes 780 mm at f/4.3.
Optical
Optical design
Hyperbolic flat-field astrograph: hyperbolic primary, flat secondary, field corrector
Effective aperture
180 mm
Focal length
500 mm
Focal ratio
f/2.8
Image circle
44 mm
Field of view
About 5°
Star size
Under 10 µm to the edge of the 44 mm image circle
With Epsilon Extender 1.5× (optional)
780 mm, f/4.3
Mechanical
Metal-back distance
56.2 mm
Focuser
Rack-and-pinion with integrated corrector and Camera Angle Adjuster
Epsilon-180ED. Metal back 56.2 mm. CAA included on focuser. Extender 1.5x optional (780 mm f/4.3). Takahashi Europe page text mistakenly says 'Epsilon-130D has a focal ratio of F/2.8'; 180ED figures used.
Takahashi Epsilon-180ED — 180 mm f/2.8 hyperbolic flat-field astrograph The Epsilon-180ED is the fastest of Takahashi's Epsilon astrographs. A 180 mm hyperbolic primary and an integrated corrector deliver 500 mm at f/2.8 with a flat 44 mm image circle, which makes it a short-exposure, wide-field workhorse for nebulae and star fields.
Manufacturer model: Takahashi Epsilon-180ED · Specifications checked against manufacturer data on 2026-11-03