telescopecomparison · 2-way
Celestron EdgeHD 9.25 vs Celestron RASA 11
Celestron
EdgeHD 9.25
Best suited for experienced imagers chasing detail running a backyard imaging setup.
Celestron
RASA 11
Best suited for intermediate imagers building a versatile kit running a permanent observatory setup.
Key differences
+279% focal length
-16% aperture
Slower by 7.8 f-stops
Specifications
| Specification | Celestron EdgeHD 9.25 | Celestron RASA 11 |
|---|---|---|
| Optics | ||
| Type | SCT | astrograph |
| Optical design | Aplanatic SCT | Rowe-Ackermann Schmidt Astrograph |
| Aperture | 235mm | 279mm |
| Focal length | 2350mm | 620mm |
| Native f/ratio | f/10.0 | f/2.2 |
| Image circle | 42mm | 43mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 9.5kg | 20.0kg |
Advantages of Celestron EdgeHD 9.25
- Tighter framing — 2350mm vs 620mm focal length
- Lighter (9.5kg vs 20kg) — easier to travel with
Advantages of Celestron RASA 11
- Wider field — 620mm vs 2350mm focal length
- 19% more light-gathering aperture
- Faster optics at f/2.22 vs f/10
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 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 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 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 EdgeHD 9.25 — 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.