telescopecomparison · 2-way
Takahashi FC-100DL vs Vixen SD103S

Takahashi
FC-100DL
Best suited for intermediate imagers building a versatile kit running a portable travel rig.

Vixen
SD103S
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Key differences
+13% focal length
Slower by 1.3 f-stops
Specifications
| Specification | Takahashi FC-100DL | Vixen SD103S |
|---|---|---|
| Optics | ||
| Type | refractor | refractor |
| Optical design | Apo doublet fluorite | Apo doublet SD |
| Aperture | 100mm | 103mm |
| Focal length | 900mm | 795mm |
| Native f/ratio | f/9.0 | f/7.7 |
| Image circle | 44mm | 44mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 3.3kg | 4.0kg |
Advantages of Takahashi FC-100DL
- Tighter framing — 900mm vs 795mm focal length
- Lighter (3.3kg vs 4kg) — easier to travel with
Advantages of Vixen SD103S
- Wider field — 795mm vs 900mm focal length
- Faster optics at f/7.7 vs f/9
Best for — Takahashi FC-100DL
- Medium-sized galaxies and planetary nebulae
- High-resolution long-exposure work
Best for — Vixen SD103S
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Takahashi FC-100DL — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.29° × 1.53°Scale: 0.86"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.50° × 1.00°Scale: 0.86"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.72° × 0.72°Scale: 0.86"/px
Vixen SD103S — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.59° × 1.73°Scale: 0.98"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.69° × 1.13°Scale: 0.98"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.81° × 0.81°Scale: 0.98"/px
Takahashi FC-100DL — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Vixen SD103S — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
