telescopecomparison · 2-way
William Optics GT 102 vs Explore Scientific ED80 FCD-100
William Optics
GT 102
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Explore Scientific
ED80 FCD-100
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Key differences
+46% focal length
+28% aperture
Slower by 0.9 f-stops
Specifications
| Specification | William Optics GT 102 | Explore Scientific ED80 FCD-100 |
|---|---|---|
| Optics | ||
| Type | refractor | refractor |
| Optical design | Apo triplet FPL-53 | Apo triplet FCD-100 |
| Aperture | 102mm | 80mm |
| Focal length | 703mm | 480mm |
| Native f/ratio | f/6.9 | f/6.0 |
| Image circle | 44mm | 44mm |
| Full-frame support | Yes | No |
| Physical | ||
| Weight | 5.6kg | 4.5kg |
Advantages of William Optics GT 102
- Tighter framing — 703mm vs 480mm focal length
- 28% more light-gathering aperture
Advantages of Explore Scientific ED80 FCD-100
- Wider field — 480mm vs 703mm focal length
- Faster optics at f/6 vs f/6.9
- Lighter (4.5kg 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 — Explore Scientific ED80 FCD-100
- Large emission nebulae and star clusters
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
Explore Scientific ED80 FCD-100 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 4.30° × 2.86°Scale: 1.62"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.81° × 1.87°Scale: 1.62"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.35° × 1.35°Scale: 1.62"/px
William Optics GT 102 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Explore Scientific ED80 FCD-100 — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.