telescopecomparison · 2-way
Takahashi FC-100DZ vs William Optics GT 102
Takahashi
FC-100DZ
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
William Optics
GT 102
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Key differences
+14% focal length
Slower by 1.1 f-stops
Specifications
| Specification | Takahashi FC-100DZ | William Optics GT 102 |
|---|---|---|
| Optics | ||
| Type | refractor | refractor |
| Optical design | Apo doublet fluorite | Apo triplet FPL-53 |
| Aperture | 100mm | 102mm |
| Focal length | 800mm | 703mm |
| Native f/ratio | f/8.0 | f/6.9 |
| Image circle | 44mm | 44mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 3.3kg | 5.6kg |
Advantages of Takahashi FC-100DZ
- Tighter framing — 800mm vs 703mm focal length
- Lighter (3.3kg vs 5.6kg) — easier to travel with
Advantages of William Optics GT 102
- Wider field — 703mm vs 800mm focal length
- Faster optics at f/6.9 vs f/8
Best for — Takahashi FC-100DZ
- Medium-sized galaxies and planetary nebulae
- High-resolution long-exposure work
Best for — William Optics GT 102
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Takahashi FC-100DZ — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.58° × 1.72°Scale: 0.97"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.68° × 1.12°Scale: 0.97"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.81° × 0.81°Scale: 0.97"/px
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
Takahashi FC-100DZ — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
William Optics GT 102 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.