telescopecomparison · 2-way
Celestron RASA 8 vs Celestron C9.25 SCT
Celestron
RASA 8
Best suited for beginners and wide-field enthusiasts running a backyard imaging setup.
Celestron
C9.25 SCT
Best suited for experienced imagers chasing detail running a backyard imaging setup.
Key differences
-83% focal length
-14% aperture
Faster by 8.0 f-stops
Specifications
| Specification | Celestron RASA 8 | Celestron C9.25 SCT |
|---|---|---|
| Optics | ||
| Type | SCT | sct |
| Optical design | Rowe-Ackermann Schmidt | Schmidt-Cassegrain |
| Aperture | 203mm | 235mm |
| Focal length | 400mm | 2350mm |
| Native f/ratio | f/2.0 | f/10.0 |
| Image circle | 32mm | — |
| Full-frame support | No | No |
| Physical | ||
| Weight | 7.7kg | 9.5kg |
Advantages of Celestron RASA 8
- Wider field — 400mm vs 2350mm focal length
- Faster optics at f/2 vs f/10
- Larger image circle (32mm) — supports bigger sensors
- Lighter (7.7kg vs 9.5kg) — easier to travel with
Advantages of Celestron C9.25 SCT
- Tighter framing — 2350mm vs 400mm focal length
- 16% more light-gathering aperture
Best for — Celestron RASA 8
- Large emission nebulae and star clusters
- Fast imaging — short exposures per sub
- Faint-object imaging under dark skies
Best for — Celestron C9.25 SCT
- Small galaxies, planetary nebulae, lunar & planetary detail
- High-resolution long-exposure work
- Faint-object imaging under dark skies
Celestron RASA 8 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 5.16° × 3.44°Scale: 1.94"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 3.37° × 2.25°Scale: 1.94"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.62° × 1.62°Scale: 1.94"/px
Celestron C9.25 SCT — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 0.88° × 0.59°Scale: 0.33"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 0.57° × 0.38°Scale: 0.33"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.28° × 0.28°Scale: 0.33"/px
Celestron RASA 8 — recommended user
Best suited for beginners and wide-field enthusiasts running a backyard imaging setup.
Celestron C9.25 SCT — recommended user
Best suited for experienced imagers chasing detail running a backyard imaging setup.