The catadioptric telescopes of the Epsilon series are wide-field astrographs with an hyperbolic primary mirror. A corrector is integrated in the rack-and-pinion focuser and offers a flat field with stars less than 10μm at the edge of the 44mm image circle.
The Epsilon-130D has a focal ratio of F/2.8. Its very short focal length of 500 mm offers a field of view of 5° and is therefore ideal for imaging large areas of stars and nebulae. Its secondary mirror is mounted on a reinforced spider to avoid any flexion. The rack-and-pinion focuser is equipped with a CAA (Camera Angle Adjuster) for photographic framing.
The primary mirror cell is equipped with 3 double-action adjusting screws (push/pull) with lock nut for pressure adjustment to minimise stress.
The collimation of the Epsilon-180ED is very easy because it does not need to be done on a star. The optical axis is represented by markings on the 2 mirrors. Takahashi has designed a simple collimation eyepiece system particularly adapted to the Epsilon allowing the adjustment of the mirrors in daylight, a big advantage compared to a classical telescope.
Regardless of its photographic qualities, the Epsilon is a first-rate wide-field observation telescope. The observation of star clusters and galaxies will give you intense pleasure due to the fineness of the stars. It proves to be a fabulous instrument for the deep sky and the search for comets. The observation of the Lagoon and Trifide nebulae in the same field is extraordinary and striking.
Takahashi Epsilon-180ED reflector
| CHARACTERISTICS | TAKAHASHI EPSILON-180ED REFLECTOR |
| Optical design | Modified hyperbolic Newtonian |
| Combination | Hyperbolic primary mirror + flat secondary mirror + field flattener |
| Diameter | 180 mm |
| AT PRIME FOCUS | |
| Focal length | 500 mm |
| Focal ratio | F/2.8 |
| Image circle diameter | 44 mm |
| Metal back distance | 56.2 mm |
Takahashi Epsilon-180ED reflector
| CHARACTERISTIC | TAKAHASHI EPSILON-180ED REFLECTOR |
| Length of the optical tube assembly | 570 mm |
| Diameter of the optical tube assembly | 232 mm |
| Weight | 10.7 kg |

Spot-diagram of the Takahashi Epsilon-180ED reflector at prime focus