cameracomparison · 2-way
ZWO ASI294MM Pro vs ZWO ASI178MM
ZWO
ASI294MM Pro
A strong fit for dedicated deep-sky imagers pairing with a broad range of focal lengths.
ZWO
ASI178MM
A strong fit for photographers stepping into astro pairing with longer focal lengths where framing is tight.
Key differences
160% larger sensor
Larger pixels (4.63µm vs 2.4µm)
631% more resolution
Cooled sensor
Specifications
| Specification | ZWO ASI294MM Pro | ZWO ASI178MM |
|---|---|---|
| Sensor | ||
| Type | Dedicated Cooled | dedicated |
| Sensor | Sony IMX492 | Sony IMX178 |
| Sensor tech | CMOS | CMOS |
| Format | 4/3" | 1/1.8" |
| Sensor size | 19.1×13.0mm | 7.4×4.9mm |
| Diagonal | 23.1mm | 8.9mm |
| Pixel size | 4.63µm | 2.40µm |
| Resolution | 8288×5644 | 3096×2080 |
| Megapixels | 46.8MP | 6.4MP |
| Color | No | No |
| Cooling | ||
| Cooled | Yes | No |
| Performance | ||
| Full well | 63700e⁻ | 15000e⁻ |
| Peak QE | 75% | 81% |
Advantages of ZWO ASI294MM Pro
- Larger sensor (23.1mm vs 8.9mm diagonal) — wider field
- Larger pixels — better low-light per-pixel sensitivity
- Higher resolution (46.8MP vs 6.4MP)
- Regulated cooling for long exposures
Advantages of ZWO ASI178MM
- Finer sampling at 2.4µm pixels
Best for — ZWO ASI294MM Pro
- Balanced field for most refractors
- Fast, low-noise deep-sky at short focal lengths
- Long-exposure deep-sky under any sky
- Narrowband and LRGB workflows
Best for — ZWO ASI178MM
- Longer focal lengths — tighter framing on small targets
- Planetary and lunar high-resolution imaging
- Narrowband and LRGB workflows
ZWO ASI294MM Pro — typical FOV & scale
- On 250mm refractor (wide)FOV: 4.38° × 2.98°Scale: 3.82"/px
- On 800mm SCT reducerFOV: 1.37° × 0.93°Scale: 1.19"/px
- On 2000mm SCT nativeFOV: 0.55° × 0.37°Scale: 0.48"/px
ZWO ASI178MM — typical FOV & scale
- On 250mm refractor (wide)FOV: 1.70° × 1.12°Scale: 1.98"/px
- On 800mm SCT reducerFOV: 0.53° × 0.35°Scale: 0.62"/px
- On 2000mm SCT nativeFOV: 0.21° × 0.14°Scale: 0.25"/px
ZWO ASI294MM Pro — recommended user
A strong fit for dedicated deep-sky imagers pairing with a broad range of focal lengths.
ZWO ASI178MM — recommended user
A strong fit for photographers stepping into astro pairing with longer focal lengths where framing is tight.