telescopecomparison · 2-way
Celestron C6 SCT vs Astro-Tech AT8RC


Key differences
-8% focal length
-26% aperture
Slower by 2.0 f-stops
Specifications
| Specification | Celestron C6 SCT | Astro-Tech AT8RC |
|---|---|---|
| Optics | ||
| Type | sct | RC |
| Optical design | Schmidt-Cassegrain | Ritchey-Chrétien |
| Aperture | 150mm | 203mm |
| Focal length | 1500mm | 1624mm |
| Native f/ratio | f/10.0 | f/8.0 |
| Image circle | — | 42mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 4.5kg | 10.0kg |
Advantages of Celestron C6 SCT
- Lighter (4.5kg vs 10kg) — easier to travel with
Advantages of Astro-Tech AT8RC
- 35% more light-gathering aperture
- Faster optics at f/8 vs f/10
- Larger image circle (42mm) — supports bigger sensors
Best for — Celestron C6 SCT
- Small galaxies, planetary nebulae, lunar & planetary detail
- High-resolution long-exposure work
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
Celestron C6 SCT — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 1.38° × 0.92°Scale: 0.52"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 0.90° × 0.60°Scale: 0.52"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.43° × 0.43°Scale: 0.52"/px
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
Celestron C6 SCT — recommended user
Best suited for experienced imagers chasing detail running a portable travel rig.
Astro-Tech AT8RC — recommended user
Best suited for experienced imagers chasing detail running a backyard imaging setup.