telescopecomparison · 2-way
TS-Optics UNC 254 f/4 Newtonian Astrograph vs William Optics Pleiades 181
TS-Optics
UNC 254 f/4 Newtonian Astrograph
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
William Optics
Pleiades 181
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
Key differences
+40% aperture
Faster by 1.5 f-stops
Specifications
| Specification | TS-Optics UNC 254 f/4 Newtonian Astrograph | William Optics Pleiades 181 |
|---|---|---|
| Optics | ||
| Type | newtonian | astrograph |
| Optical design | Newtonian astrograph | Astrograph (7-element) |
| Aperture | 254mm | 181mm |
| Focal length | 1016mm | 998mm |
| Native f/ratio | f/4.0 | f/5.5 |
| Image circle | — | 55mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 14.0kg | 15.0kg |
Advantages of TS-Optics UNC 254 f/4 Newtonian Astrograph
- 40% more light-gathering aperture
- Faster optics at f/4 vs f/5.5
Advantages of William Optics Pleiades 181
- Larger image circle (55mm) — supports bigger sensors
Best for — TS-Optics UNC 254 f/4 Newtonian Astrograph
- Medium-sized galaxies and planetary nebulae
- Fast imaging — short exposures per sub
- Faint-object imaging under dark skies
- Full-frame astro cameras and DSLRs
Best for — William Optics Pleiades 181
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
TS-Optics UNC 254 f/4 Newtonian Astrograph — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.03° × 1.35°Scale: 0.76"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.33° × 0.89°Scale: 0.76"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.64° × 0.64°Scale: 0.76"/px
William Optics Pleiades 181 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.07° × 1.38°Scale: 0.78"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.35° × 0.90°Scale: 0.78"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.65° × 0.65°Scale: 0.78"/px
TS-Optics UNC 254 f/4 Newtonian Astrograph — recommended user
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
William Optics Pleiades 181 — recommended user
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
