telescopecomparison · 2-way
Vixen SD115S vs Takahashi FC-100DL
Vixen
SD115S
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Takahashi
FC-100DL
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Key differences
+15% aperture
Faster by 1.3 f-stops
Specifications
| Specification | Vixen SD115S | Takahashi FC-100DL |
|---|---|---|
| Optics | ||
| Type | refractor | refractor |
| Optical design | Apo doublet SD | Apo doublet fluorite |
| Aperture | 115mm | 100mm |
| Focal length | 890mm | 900mm |
| Native f/ratio | f/7.7 | f/9.0 |
| Image circle | 44mm | 44mm |
| Full-frame support | Yes | No |
| Physical | ||
| Weight | 4.8kg | 3.3kg |
Advantages of Vixen SD115S
- 15% more light-gathering aperture
- Faster optics at f/7.7 vs f/9
Advantages of Takahashi FC-100DL
- Lighter (3.3kg vs 4.8kg) — easier to travel with
Best for — Vixen SD115S
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Best for — Takahashi FC-100DL
- Medium-sized galaxies and planetary nebulae
- High-resolution long-exposure work
Vixen SD115S — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.32° × 1.55°Scale: 0.87"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.51° × 1.01°Scale: 0.87"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.73° × 0.73°Scale: 0.87"/px
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 SD115S — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Takahashi FC-100DL — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.