telescopecomparison · 2-way
Askar 151PHQ vs Vixen SD115S
Askar
151PHQ
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
Vixen
SD115S
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Key differences
+19% focal length
+31% aperture
Faster by 0.7 f-stops
Specifications
| Specification | Askar 151PHQ | Vixen SD115S |
|---|---|---|
| Optics | ||
| Type | refractor | refractor |
| Optical design | Petzval quintuplet FPL-51 | Apo doublet SD |
| Aperture | 151mm | 115mm |
| Focal length | 1057mm | 890mm |
| Native f/ratio | f/7.0 | f/7.7 |
| Image circle | 60mm | 44mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 15.5kg | 4.8kg |
Advantages of Askar 151PHQ
- Tighter framing — 1057mm vs 890mm focal length
- 31% more light-gathering aperture
- Faster optics at f/7 vs f/7.7
- Larger image circle (60mm) — supports bigger sensors
Advantages of Vixen SD115S
- Wider field — 890mm vs 1057mm focal length
- Lighter (4.8kg vs 15.5kg) — easier to travel with
Best for — Askar 151PHQ
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Best for — Vixen SD115S
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
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
Vixen SD115S — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.32° × 1.55°Scale: 0.87"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.51° × 1.01°Scale: 0.87"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.73° × 0.73°Scale: 0.87"/px
Askar 151PHQ — recommended user
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
Vixen SD115S — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.