telescope
William Optics
Zenithstar 61 II
61mm Apo doublet FPL-53 · 360mm f/5.9
Compact doublet astrograph.
Best for
- Large emission nebulae and star clusters
Specifications
| Optics | |
| Type | refractor |
| Optical design | Apo doublet FPL-53 |
| Aperture | 61mm |
| Focal length | 360mm |
| Native f/ratio | f/5.9 |
| Image circle | 44mm |
| Full-frame support | No |
| Physical | |
| Weight | 1.9kg |
Typical FOV & image 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
Typical targets
- IC IC 5070 — Pelican NebulaEmission Nebula · 80′
- NGC NGC 2237 — Rosette NebulaEmission Nebula · 80′
- Messier M7 — Ptolemy's ClusterOpen Cluster · 80′
- IC IC 2944 — Running Chicken NebulaEmission Nebula · 75′
- Messier M33 — Triangulum GalaxyGalaxy · 73′
- Messier M42 — Orion NebulaEmission Nebula · 85′
Recommended cameras
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