telescopecomparison · 2-way
Celestron EdgeHD 9.25 vs Celestron RASA 8
Celestron
EdgeHD 9.25
Best suited for experienced imagers chasing detail running a backyard imaging setup.
Celestron
RASA 8
Best suited for beginners and wide-field enthusiasts running a backyard imaging setup.
Key differences
+488% focal length
+16% aperture
Slower by 8.0 f-stops
Specifications
| Specification | Celestron EdgeHD 9.25 | Celestron RASA 8 |
|---|---|---|
| Optics | ||
| Type | SCT | SCT |
| Optical design | Aplanatic SCT | Rowe-Ackermann Schmidt |
| Aperture | 235mm | 203mm |
| Focal length | 2350mm | 400mm |
| Native f/ratio | f/10.0 | f/2.0 |
| Image circle | 42mm | 32mm |
| Full-frame support | Yes | No |
| Physical | ||
| Weight | 9.5kg | 7.7kg |
Advantages of Celestron EdgeHD 9.25
- Tighter framing — 2350mm vs 400mm focal length
- 16% more light-gathering aperture
- Larger image circle (42mm) — supports bigger sensors
Advantages of Celestron RASA 8
- Wider field — 400mm vs 2350mm focal length
- Faster optics at f/2 vs f/10
- Lighter (7.7kg vs 9.5kg) — easier to travel with
Best for — Celestron EdgeHD 9.25
- 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 — Celestron RASA 8
- Large emission nebulae and star clusters
- Fast imaging — short exposures per sub
- Faint-object imaging under dark skies
Celestron EdgeHD 9.25 — 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 — 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 EdgeHD 9.25 — recommended user
Best suited for experienced imagers chasing detail running a backyard imaging setup.
Celestron RASA 8 — recommended user
Best suited for beginners and wide-field enthusiasts running a backyard imaging setup.