telescopecomparison · 2-way
SharpStar 61EDPH III vs Borg 55FL
SharpStar
61EDPH III
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Key differences
+34% focal length
+11% aperture
Slower by 1.0 f-stops
Specifications
| Specification | SharpStar 61EDPH III | Borg 55FL |
|---|---|---|
| Optics | ||
| Type | Refractor | refractor |
| Optical design | Doublet APO | Apo doublet fluorite |
| Aperture | 61mm | 55mm |
| Focal length | 335mm | 250mm |
| Native f/ratio | f/5.5 | f/4.5 |
| Image circle | 32mm | — |
| Full-frame support | No | No |
| Physical | ||
| Weight | 2.4kg | 1.2kg |
Advantages of SharpStar 61EDPH III
- Tighter framing — 335mm vs 250mm focal length
- 11% more light-gathering aperture
- Larger image circle (32mm) — supports bigger sensors
Advantages of Borg 55FL
- Wider field — 250mm vs 335mm focal length
- Faster optics at f/4.5 vs f/5.5
- Lighter (1.2kg vs 2.4kg) — easier to travel with
Best for — SharpStar 61EDPH III
- Wide-field nebulae and Milky Way regions
Best for — Borg 55FL
- Wide-field nebulae and Milky Way regions
- Fast imaging — short exposures per sub
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
Borg 55FL — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 8.25° × 5.50°Scale: 3.10"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 5.39° × 3.60°Scale: 3.10"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 2.59° × 2.59°Scale: 3.10"/px
SharpStar 61EDPH III — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Borg 55FL — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
