Takahashi Epsilon-160ED (OTA only)

The Takahashi Epsilon-160ED is the modern successor to the original Epsilon-160, bringing Takahashi’s long-established hyperbolic astrograph design up to date for modern digital imaging. The 160ED combines a 160mm hyperbolic primary mirror, flat secondary mirror and dedicated two-element field corrector into a single optical system designed specifically around the requirements of modern CCD and CMOS sensors.

The result is a remarkably fast and well-corrected imaging telescope. With a 530mm focal length and f/3.3 focal ratio, the Epsilon-160ED gathers light rapidly while providing a generous 4.8° photographic field. This makes it particularly effective for large nebulae, star clusters, Milky Way fields and other deep-sky objects that benefit from a wide field of view.

The dedicated corrector is one of the defining features of the 160ED. It uses ED glass and is specifically matched to the aspherical coefficient of the Epsilon-160ED’s primary mirror. Takahashi specifies diffraction-limited star images of approximately 3 microns at the edge of the 44mm image circle, allowing the telescope to illuminate modern full-frame sensors with exceptionally fine star images. The corrector is integrated into the focuser and is an essential part of the optical system; the telescope should not be used for normal observation or imaging without it installed.

The Epsilon optical design combines the hyperbolic primary mirror with the corrector to correct spherical aberration and coma while producing a flattened image plane. Takahashi also redesigned the system to reduce distortion to approximately 0.3%, which is particularly useful for photographic mosaics, astrometric work and other applications where geometric accuracy matters.

For wide-field imaging, the secondary mirror is deliberately offset from the centre of the optical tube. This arrangement improves illumination across the image circle without requiring the secondary to be made even larger. The 63mm secondary is supported by a structure designed to maintain the optical alignment of the fast optical system.

The oversized rack-and-pinion focuser is designed to handle demanding imaging equipment. It incorporates a CAA, or Camera Angle Adjuster, allowing the camera to be rotated for composition without changing the telescope’s optical configuration. The focuser is compatible with the optional MEF-3 microfocuser, and motorised focusing options are also available.

Although the Epsilon-160ED is primarily an astrophotography instrument, it is not restricted to imaging. Takahashi provides a dedicated visual configuration using the supplied visual adapter and 31.7mm eyepiece adapter. The combination of 160mm aperture, fine optical correction and a short 530mm focal length makes it particularly effective for wide-field views of deep-sky objects. At the same time, the telescope can be used at higher magnifications when conditions and the target make this appropriate.

The Epsilon-160ED is relatively compact for a 160mm astrograph. The optical tube is 580mm long, has a main tube diameter of 204mm and weighs approximately 6.9kg. Tube rings and a finder are separate accessories and are not included with the OTA-only configuration.

Takahashi also offers a dedicated 1.5× Epsilon extender for the 160ED. This changes the focal length from 530mm to 800mm and the focal ratio from f/3.3 to f/5.0 while retaining a 44mm image circle. The extender is specifically designed for the Epsilon-160ED and is an optional accessory.