telescopecomparison · 2-way
Sky-Watcher Quattro 250P vs William Optics GT 71
Sky-Watcher
Quattro 250P
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
William Optics
GT 71
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Key differences
+138% focal length
+252% aperture
Faster by 1.9 f-stops
Specifications
| Specification | Sky-Watcher Quattro 250P | William Optics GT 71 |
|---|---|---|
| Optics | ||
| Type | newtonian | refractor |
| Optical design | Newtonian astrograph | Apo triplet FPL-53 |
| Aperture | 250mm | 71mm |
| Focal length | 1000mm | 420mm |
| Native f/ratio | f/4.0 | f/5.9 |
| Image circle | — | 44mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 15.5kg | 3.4kg |
Advantages of Sky-Watcher Quattro 250P
- Tighter framing — 1000mm vs 420mm focal length
- 252% more light-gathering aperture
- Faster optics at f/4 vs f/5.9
Advantages of William Optics GT 71
- Wider field — 420mm vs 1000mm focal length
- Larger image circle (44mm) — supports bigger sensors
- Lighter (3.4kg vs 15.5kg) — easier to travel with
Best for — Sky-Watcher Quattro 250P
- 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 GT 71
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
Sky-Watcher Quattro 250P — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.06° × 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
William Optics GT 71 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 4.91° × 3.27°Scale: 1.85"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 3.21° × 2.14°Scale: 1.85"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.54° × 1.54°Scale: 1.85"/px
Sky-Watcher Quattro 250P — recommended user
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
William Optics GT 71 — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.