telescopecomparison · 2-way
Celestron C8 SCT vs Celestron RASA 11
Celestron
RASA 11
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
Key differences
+228% focal length
-27% aperture
Slower by 7.8 f-stops
Specifications
| Specification | Celestron C8 SCT | Celestron RASA 11 |
|---|---|---|
| Optics | ||
| Type | sct | astrograph |
| Optical design | Schmidt-Cassegrain | Rowe-Ackermann Schmidt Astrograph |
| Aperture | 203mm | 279mm |
| Focal length | 2032mm | 620mm |
| Native f/ratio | f/10.0 | f/2.2 |
| Image circle | — | 43mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 5.7kg | 20.0kg |
Advantages of Celestron C8 SCT
- Tighter framing — 2032mm vs 620mm focal length
- Lighter (5.7kg vs 20kg) — easier to travel with
Advantages of Celestron RASA 11
- Wider field — 620mm vs 2032mm focal length
- 37% more light-gathering aperture
- Faster optics at f/2.22 vs f/10
- Larger image circle (43mm) — supports bigger sensors
Best for — Celestron C8 SCT
- Small galaxies, planetary nebulae, lunar & planetary detail
- High-resolution long-exposure work
- Faint-object imaging under dark skies
Best for — Celestron RASA 11
- Large emission nebulae and star clusters
- Fast imaging — short exposures per sub
- Faint-object imaging under dark skies
- Full-frame astro cameras and DSLRs
Celestron C8 SCT — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 1.02° × 0.68°Scale: 0.38"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 0.66° × 0.44°Scale: 0.38"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.32° × 0.32°Scale: 0.38"/px
Celestron RASA 11 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 3.33° × 2.22°Scale: 1.25"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.17° × 1.45°Scale: 1.25"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.04° × 1.04°Scale: 1.25"/px
Celestron C8 SCT — recommended user
Best suited for experienced imagers chasing detail running a backyard imaging setup.
Celestron RASA 11 — recommended user
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.