telescopecomparison · 2-way
William Optics Zenithstar 61 II vs Askar 65PHQ
William Optics
Zenithstar 61 II
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Key differences
-13% focal length
-6% aperture
Faster by 0.5 f-stops
Specifications
| Specification | William Optics Zenithstar 61 II | Askar 65PHQ |
|---|---|---|
| Optics | ||
| Type | refractor | Refractor |
| Optical design | Apo doublet FPL-53 | Quintuplet Petzval |
| Aperture | 61mm | 65mm |
| Focal length | 360mm | 416mm |
| Native f/ratio | f/5.9 | f/6.4 |
| Image circle | 44mm | 44mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 1.9kg | 3.6kg |
Advantages of William Optics Zenithstar 61 II
- Wider field — 360mm vs 416mm focal length
- Faster optics at f/5.9 vs f/6.4
- Lighter (1.9kg vs 3.6kg) — easier to travel with
Advantages of Askar 65PHQ
- Tighter framing — 416mm vs 360mm focal length
Best for — William Optics Zenithstar 61 II
- Large emission nebulae and star clusters
Best for — Askar 65PHQ
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
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
Askar 65PHQ — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 4.96° × 3.31°Scale: 1.86"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 3.24° × 2.16°Scale: 1.86"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.56° × 1.56°Scale: 1.86"/px
William Optics Zenithstar 61 II — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Askar 65PHQ — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.