telescopecomparison · 2-way
Celestron RASA 8 vs Takahashi FSQ-85EDX
Celestron
RASA 8
Best suited for beginners and wide-field enthusiasts running a backyard imaging setup.
Takahashi
FSQ-85EDX
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Key differences
-11% focal length
+139% aperture
Faster by 3.3 f-stops
Specifications
| Specification | Celestron RASA 8 | Takahashi FSQ-85EDX |
|---|---|---|
| Optics | ||
| Type | SCT | Refractor |
| Optical design | Rowe-Ackermann Schmidt | Petzval APO |
| Aperture | 203mm | 85mm |
| Focal length | 400mm | 450mm |
| Native f/ratio | f/2.0 | f/5.3 |
| Image circle | 32mm | 44mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 7.7kg | 4.0kg |
Advantages of Celestron RASA 8
- Wider field — 400mm vs 450mm focal length
- 139% more light-gathering aperture
- Faster optics at f/2 vs f/5.3
Advantages of Takahashi FSQ-85EDX
- Tighter framing — 450mm vs 400mm focal length
- Larger image circle (44mm) — supports bigger sensors
- Lighter (4kg vs 7.7kg) — easier to travel with
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 — Takahashi FSQ-85EDX
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
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
Takahashi FSQ-85EDX — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 4.58° × 3.06°Scale: 1.72"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.99° × 2.00°Scale: 1.72"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.44° × 1.44°Scale: 1.72"/px
Celestron RASA 8 — recommended user
Best suited for beginners and wide-field enthusiasts running a backyard imaging setup.
Takahashi FSQ-85EDX — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.