telescope
William Optics
RedCat 61
61mm Petzval APO · 300mm f/4.9
Petzval astrograph; native full-frame.
Best for
- Wide-field nebulae and Milky Way regions
- Fast imaging — short exposures per sub
- Full-frame astro cameras and DSLRs
Specifications
| Optics | |
| Type | Refractor |
| Optical design | Petzval APO |
| Aperture | 61mm |
| Focal length | 300mm |
| Native f/ratio | f/4.9 |
| Image circle | 45mm |
| Full-frame support | Yes |
| Physical | |
| Weight | 2.0kg |
Typical FOV & image scale
With Full-frame (36×24mm, 3.76µm)
FOV 6.88° × 4.58°
Scale 2.59″/px
With APS-C (23.5×15.7mm, 3.76µm)
FOV 4.49° × 3.00°
Scale 2.59″/px
With IMX533 square (11.3×11.3mm, 3.76µm)
FOV 2.16° × 2.16°
Scale 2.59″/px
Recommended accessories
- William Optics Flat 6AIIIflattener · 1× focal lengthcommunity reported
Typical targets
- Messier M44 — Beehive ClusterOpen Cluster · 95′
- Messier M8 — Lagoon NebulaEmission Nebula · 90′
- Messier M24 — Sagittarius Star CloudOpen Cluster · 90′
- Messier M42 — Orion NebulaEmission Nebula · 85′
- IC IC 5070 — Pelican NebulaEmission Nebula · 80′
- NGC NGC 2237 — Rosette NebulaEmission Nebula · 80′
Recommended cameras
28.4mm sensor · 4.78µm px · cooled
Compare pairing28.3mm sensor · 3.76µm px · cooled
Compare pairing28.3mm sensor · 3.76µm px · cooled
Compare pairing