telescopecomparison · 2-way
Borg 55FL vs Borg 107FL


Borg
107FL
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Key differences
-58% focal length
-49% aperture
Faster by 1.1 f-stops
Specifications
| Specification | Borg 55FL | Borg 107FL |
|---|---|---|
| Optics | ||
| Type | refractor | refractor |
| Optical design | Apo doublet fluorite | Apo doublet fluorite |
| Aperture | 55mm | 107mm |
| Focal length | 250mm | 600mm |
| Native f/ratio | f/4.5 | f/5.6 |
| Image circle | — | — |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 1.2kg | 3.5kg |
Advantages of Borg 55FL
- Wider field — 250mm vs 600mm focal length
- Faster optics at f/4.5 vs f/5.6
- Lighter (1.2kg vs 3.5kg) — easier to travel with
Advantages of Borg 107FL
- Tighter framing — 600mm vs 250mm focal length
- 95% more light-gathering aperture
Best for — Borg 55FL
- Wide-field nebulae and Milky Way regions
- Fast imaging — short exposures per sub
Best for — Borg 107FL
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
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
Borg 107FL — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 3.44° × 2.29°Scale: 1.29"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.24° × 1.50°Scale: 1.29"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.08° × 1.08°Scale: 1.29"/px
Borg 55FL — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Borg 107FL — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.