telescopecomparison · 2-way
SharpStar 61EDPH III vs William Optics RedCat 61

SharpStar
61EDPH III
Best suited for beginners and wide-field enthusiasts running a portable travel rig.

William Optics
RedCat 61
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Key differences
+12% focal length
Slower by 0.6 f-stops
Specifications
| Specification | SharpStar 61EDPH III | William Optics RedCat 61 |
|---|---|---|
| Optics | ||
| Type | Refractor | Refractor |
| Optical design | Doublet APO | Petzval APO |
| Aperture | 61mm | 61mm |
| Focal length | 335mm | 300mm |
| Native f/ratio | f/5.5 | f/4.9 |
| Image circle | 32mm | 45mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 2.4kg | 2.0kg |
Advantages of SharpStar 61EDPH III
- Tighter framing — 335mm vs 300mm focal length
Advantages of William Optics RedCat 61
- Wider field — 300mm vs 335mm focal length
- Faster optics at f/4.9 vs f/5.5
- Larger image circle (45mm) — supports bigger sensors
- Lighter (2kg vs 2.4kg) — easier to travel with
Best for — SharpStar 61EDPH III
- Wide-field nebulae and Milky Way regions
Best for — William Optics RedCat 61
- Wide-field nebulae and Milky Way regions
- Fast imaging — short exposures per sub
- Full-frame astro cameras and DSLRs
SharpStar 61EDPH III — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 6.16° × 4.11°Scale: 2.32"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 4.02° × 2.69°Scale: 2.32"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.93° × 1.93°Scale: 2.32"/px
William Optics RedCat 61 — typical FOV & 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
SharpStar 61EDPH III — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
William Optics RedCat 61 — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.