telescopecomparison · 2-way
Astro-Tech AT8RC vs Askar 120APO
Askar
120APO
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Key differences
+93% focal length
+69% aperture
Slower by 1.0 f-stops
Specifications
| Specification | Astro-Tech AT8RC | Askar 120APO |
|---|---|---|
| Optics | ||
| Type | RC | Refractor |
| Optical design | Ritchey-Chrétien | Triplet APO |
| Aperture | 203mm | 120mm |
| Focal length | 1624mm | 840mm |
| Native f/ratio | f/8.0 | f/7.0 |
| Image circle | 42mm | 44mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 10.0kg | 8.5kg |
Advantages of Astro-Tech AT8RC
- Tighter framing — 1624mm vs 840mm focal length
- 69% more light-gathering aperture
Advantages of Askar 120APO
- Wider field — 840mm vs 1624mm focal length
- Faster optics at f/7 vs f/8
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 — Askar 120APO
- 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
Askar 120APO — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.46° × 1.64°Scale: 0.92"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.60° × 1.07°Scale: 0.92"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.77° × 0.77°Scale: 0.92"/px
Astro-Tech AT8RC — recommended user
Best suited for experienced imagers chasing detail running a backyard imaging setup.
Askar 120APO — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.