telescopecomparison · 2-way
Takahashi TSA-120 vs Takahashi FC-100DZ
Takahashi
TSA-120
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Takahashi
FC-100DZ
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Key differences
+13% focal length
+20% aperture
Faster by 0.5 f-stops
Specifications
| Specification | Takahashi TSA-120 | Takahashi FC-100DZ |
|---|---|---|
| Optics | ||
| Type | Refractor | refractor |
| Optical design | Triplet APO | Apo doublet fluorite |
| Aperture | 120mm | 100mm |
| Focal length | 900mm | 800mm |
| Native f/ratio | f/7.5 | f/8.0 |
| Image circle | 44mm | 44mm |
| Full-frame support | Yes | No |
| Physical | ||
| Weight | 7.5kg | 3.3kg |
Advantages of Takahashi TSA-120
- Tighter framing — 900mm vs 800mm focal length
- 20% more light-gathering aperture
- Faster optics at f/7.5 vs f/8
Advantages of Takahashi FC-100DZ
- Wider field — 800mm vs 900mm focal length
- Lighter (3.3kg vs 7.5kg) — easier to travel with
Best for — Takahashi TSA-120
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Best for — Takahashi FC-100DZ
- Medium-sized galaxies and planetary nebulae
- High-resolution long-exposure work
Takahashi TSA-120 — 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
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
Takahashi TSA-120 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Takahashi FC-100DZ — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.