telescopecomparison · 2-way
William Optics Zenithstar 61 II vs Radian Raptor 61
William Optics
Zenithstar 61 II
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Key differences
+31% focal length
Slower by 1.4 f-stops
Specifications
| Specification | William Optics Zenithstar 61 II | Radian Raptor 61 |
|---|---|---|
| Optics | ||
| Type | refractor | refractor |
| Optical design | Apo doublet FPL-53 | Petzval quadruplet |
| Aperture | 61mm | 61mm |
| Focal length | 360mm | 275mm |
| Native f/ratio | f/5.9 | f/4.5 |
| Image circle | 44mm | 44mm |
| Full-frame support | No | No |
| Physical | ||
| Weight | 1.9kg | 2.6kg |
Advantages of William Optics Zenithstar 61 II
- Tighter framing — 360mm vs 275mm focal length
- Lighter (1.9kg vs 2.6kg) — easier to travel with
Advantages of Radian Raptor 61
- Wider field — 275mm vs 360mm focal length
- Faster optics at f/4.5 vs f/5.9
Best for — William Optics Zenithstar 61 II
- Large emission nebulae and star clusters
Best for — Radian Raptor 61
- Wide-field nebulae and Milky Way regions
- Fast imaging — short exposures per sub
William Optics Zenithstar 61 II — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 5.73° × 3.82°Scale: 2.15"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 3.74° × 2.50°Scale: 2.15"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.80° × 1.80°Scale: 2.15"/px
Radian Raptor 61 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 7.50° × 5.00°Scale: 2.82"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 4.90° × 3.27°Scale: 2.82"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 2.35° × 2.35°Scale: 2.82"/px
William Optics Zenithstar 61 II — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Radian Raptor 61 — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.