telescopecomparison · 2-way
Astro-Tech AT8RC vs Takahashi TSA-120
Takahashi
TSA-120
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Key differences
+80% focal length
+69% aperture
Slower by 0.5 f-stops
Specifications
| Specification | Astro-Tech AT8RC | Takahashi TSA-120 |
|---|---|---|
| Optics | ||
| Type | RC | Refractor |
| Optical design | Ritchey-Chrétien | Triplet APO |
| Aperture | 203mm | 120mm |
| Focal length | 1624mm | 900mm |
| Native f/ratio | f/8.0 | f/7.5 |
| Image circle | 42mm | 44mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 10.0kg | 7.5kg |
Advantages of Astro-Tech AT8RC
- Tighter framing — 1624mm vs 900mm focal length
- 69% more light-gathering aperture
Advantages of Takahashi TSA-120
- Wider field — 900mm vs 1624mm focal length
- Faster optics at f/7.5 vs f/8
- Lighter (7.5kg vs 10kg) — easier to travel with
Best for — Astro-Tech AT8RC
- Small galaxies, planetary nebulae, lunar & planetary detail
- High-resolution long-exposure work
- Faint-object imaging under dark skies
- Full-frame astro cameras and DSLRs
Best for — Takahashi TSA-120
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Astro-Tech AT8RC — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 1.27° × 0.85°Scale: 0.48"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 0.83° × 0.55°Scale: 0.48"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.40° × 0.40°Scale: 0.48"/px
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
Astro-Tech AT8RC — recommended user
Best suited for experienced imagers chasing detail running a backyard imaging setup.
Takahashi TSA-120 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.