telescopecomparison · 2-way
William Optics Zenithstar 73 II vs Askar 65PHQ
William Optics
Zenithstar 73 II
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Key differences
+12% aperture
Faster by 0.5 f-stops
Specifications
| Specification | William Optics Zenithstar 73 II | Askar 65PHQ |
|---|---|---|
| Optics | ||
| Type | refractor | Refractor |
| Optical design | Apo doublet FPL-53 | Quintuplet Petzval |
| Aperture | 73mm | 65mm |
| Focal length | 430mm | 416mm |
| Native f/ratio | f/5.9 | f/6.4 |
| Image circle | 44mm | 44mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 2.4kg | 3.6kg |
Advantages of William Optics Zenithstar 73 II
- 12% more light-gathering aperture
- Faster optics at f/5.9 vs f/6.4
- Lighter (2.4kg vs 3.6kg) — easier to travel with
Advantages of Askar 65PHQ
Closely matched on the compared specs.
Best for — William Optics Zenithstar 73 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 73 II — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 4.80° × 3.20°Scale: 1.80"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 3.13° × 2.09°Scale: 1.80"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.51° × 1.51°Scale: 1.80"/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 73 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.