Takahashi Epsilon-130D — 130 mm f/3.3 hyperbolic flat-field astrograph The Epsilon-130D is the most compact member of Takahashi's Epsilon series of hyperbolic astrographs. It pairs a 130 mm hyperbolic primary mirror with a flat secondary and a two-element corrector built into the focuser, giving a 430 mm f/3.3 system that covers a full-frame sensor.
Manufacturer model: Takahashi Epsilon-130D · Specifications checked against manufacturer data on 2026-11-03
The Epsilon-130D is the most compact member of Takahashi's Epsilon series of hyperbolic astrographs. It pairs a 130 mm hyperbolic primary mirror with a flat secondary and a two-element corrector built into the focuser, giving a 430 mm f/3.3 system that covers a full-frame sensor.
Takahashi's Epsilon design uses a hyperbolic primary mirror to correct spherical aberration and coma, while the corrector flattens the field. Takahashi states that the 130D keeps star images under 10 µm out to the edge of the 44 mm image circle. Compared with the original Epsilon-130, the redesigned doublet corrector cuts the smallest star size to less than a third and halves distortion, which makes mosaic assembly easier.
At 430 mm, the 130D gives a 5.9° photographic field, well suited to large nebulae and star fields. The tube assembly weighs about 4.9 kg, so it is easy to transport and suits medium-sized mounts. The secondary mirror sits on a reinforced spider to prevent flexure.
The metal-back distance is 56.2 mm at prime focus. At f/3.3 the depth of focus is very shallow, so Takahashi recommends a fine-focusing system, such as the optional MEF-3 micro focuser or an electronic focuser. The optional Epsilon Extender 1.5× E-130D converts the system to 650 mm at f/5.0 while keeping the 44 mm image circle. The oversized primary mirror needs time to reach ambient temperature before imaging.
| Optical design | Hyperbolic flat-field astrograph: hyperbolic primary, flat secondary, field corrector |
|---|---|
| Effective aperture | 130 mm |
| Focal length | 430 mm |
| Focal ratio | f/3.3 |
| Secondary mirror minor axis | 63 mm |
| Corrector | 2 elements in 2 groups |
| Image circle | 44 mm |
| Photographic field | 5.9° |
| Star size | Under 10 µm to the edge of the 44 mm image circle |
| With Extender 1.5× E-130D (optional) | 650 mm, f/5.0, 44 mm image circle |
| Metal-back distance | 56.2 mm |
|---|---|
| Focuser | Rack-and-pinion with integrated corrector |
| Tube diameter | 166 mm (front end 188 mm) |
| Tube assembly length | 460 mm |
| Tube assembly weight | Approximately 4.9 kg |
| Takahashi Europe codes | TEK13000 (reflector); TEK13010 (OTA) |
Takahashi Europe Epsilon-130D specifications · Epsilon-130D instruction manual · Takahashi 2025 catalogue
Epsilon-130D (current D version), not the original Epsilon-130. Metal back 56.2 mm (some older documents round to 56 mm). Extender 1.5x E-130D is optional. Fine focuser recommended at f/3.3. Supplied accessory package varies between reflector (TEK13000) and OTA (TEK13010) codes; confirm which is supplied.
| Secondary mirror (mm) | 63 |
|---|---|
| Photographic field (°) | 5.9 |
| Star size | Under 10 um to edge of 44 mm image circle |
| Metal back (mm) | 56.2 |
| Optional extender | Extender 1.5x E-130D: 650 mm, f/5.0, 44 mm image circle |
| Europe codes | TEK13000 reflector; TEK13010 OTA |
Ficha técnica
Takahashi Epsilon-130D — 130 mm f/3.3 hyperbolic flat-field astrograph The Epsilon-130D is the most compact member of Takahashi's Epsilon series of hyperbolic astrographs. It pairs a 130 mm hyperbolic primary mirror with a flat secondary and a two-element corrector built into the focuser, giving a 430 mm f/3.3 system that covers a full-frame sensor.
Manufacturer model: Takahashi Epsilon-130D · Specifications checked against manufacturer data on 2026-11-03
