telescopecomparison · 2-way
William Optics GT 102 vs Borg 107FL
William Optics
GT 102
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Borg
107FL
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Key differences
+17% focal length
Slower by 1.3 f-stops
Specifications
| Specification | William Optics GT 102 | Borg 107FL |
|---|---|---|
| Optics | ||
| Type | refractor | refractor |
| Optical design | Apo triplet FPL-53 | Apo doublet fluorite |
| Aperture | 102mm | 107mm |
| Focal length | 703mm | 600mm |
| Native f/ratio | f/6.9 | f/5.6 |
| Image circle | 44mm | — |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 5.6kg | 3.5kg |
Advantages of William Optics GT 102
- Tighter framing — 703mm vs 600mm focal length
- Larger image circle (44mm) — supports bigger sensors
Advantages of Borg 107FL
- Wider field — 600mm vs 703mm focal length
- Faster optics at f/5.6 vs f/6.9
- Lighter (3.5kg vs 5.6kg) — easier to travel with
Best for — William Optics GT 102
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Best for — Borg 107FL
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
William Optics GT 102 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.93° × 1.96°Scale: 1.10"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.92° × 1.28°Scale: 1.10"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.92° × 0.92°Scale: 1.10"/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
William Optics GT 102 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Borg 107FL — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.