telescopecomparison · 2-way
William Optics Pleiades 181 vs Askar 151PHQ
William Optics
Pleiades 181
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
Askar
151PHQ
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
Key differences
-6% focal length
+20% aperture
Faster by 1.5 f-stops
Specifications
| Specification | William Optics Pleiades 181 | Askar 151PHQ |
|---|---|---|
| Optics | ||
| Type | astrograph | refractor |
| Optical design | Astrograph (7-element) | Petzval quintuplet FPL-51 |
| Aperture | 181mm | 151mm |
| Focal length | 998mm | 1057mm |
| Native f/ratio | f/5.5 | f/7.0 |
| Image circle | 55mm | 60mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 15.0kg | 15.5kg |
Advantages of William Optics Pleiades 181
- 20% more light-gathering aperture
- Faster optics at f/5.5 vs f/7
Advantages of Askar 151PHQ
Closely matched on the compared specs.
Best for — William Optics Pleiades 181
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Best for — Askar 151PHQ
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
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
Askar 151PHQ — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 1.95° × 1.30°Scale: 0.73"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.27° × 0.85°Scale: 0.73"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.61° × 0.61°Scale: 0.73"/px
William Optics Pleiades 181 — recommended user
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
Askar 151PHQ — recommended user
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
