telescopecomparison · 2-way
Takahashi Epsilon-180ED vs William Optics Ultra-Cat 131
Takahashi
Epsilon-180ED
Best suited for beginners and wide-field enthusiasts running a permanent observatory setup.
William Optics
Ultra-Cat 131
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Key differences
-23% focal length
+37% aperture
Faster by 2.1 f-stops
Specifications
| Specification | Takahashi Epsilon-180ED | William Optics Ultra-Cat 131 |
|---|---|---|
| Optics | ||
| Type | astrograph | refractor |
| Optical design | Hyperbolic Newtonian | Petzval (5-element advanced) |
| Aperture | 180mm | 131mm |
| Focal length | 500mm | 648mm |
| Native f/ratio | f/2.8 | f/4.9 |
| Image circle | 44mm | 60mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 12.5kg | 11.3kg |
Advantages of Takahashi Epsilon-180ED
- Wider field — 500mm vs 648mm focal length
- 37% more light-gathering aperture
- Faster optics at f/2.8 vs f/4.9
Advantages of William Optics Ultra-Cat 131
- Tighter framing — 648mm vs 500mm focal length
- Larger image circle (60mm) — supports bigger sensors
Best for — Takahashi Epsilon-180ED
- Large emission nebulae and star clusters
- Fast imaging — short exposures per sub
- Full-frame astro cameras and DSLRs
Best for — William Optics Ultra-Cat 131
- Large emission nebulae and star clusters
- Fast imaging — short exposures per sub
- Full-frame astro cameras and DSLRs
Takahashi Epsilon-180ED — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 4.13° × 2.75°Scale: 1.55"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.69° × 1.80°Scale: 1.55"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.29° × 1.29°Scale: 1.55"/px
William Optics Ultra-Cat 131 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 3.18° × 2.12°Scale: 1.20"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.08° × 1.39°Scale: 1.20"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.00° × 1.00°Scale: 1.20"/px
Takahashi Epsilon-180ED — recommended user
Best suited for beginners and wide-field enthusiasts running a permanent observatory setup.
William Optics Ultra-Cat 131 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
