cameracomparison · 2-way
ZWO ASI178MM vs ZWO ASI294MC Air
ZWO
ASI178MM
A strong fit for photographers stepping into astro pairing with longer focal lengths where framing is tight.
ZWO
ASI294MC Air
A strong fit for dedicated deep-sky imagers pairing with a broad range of focal lengths.
Key differences
-62% larger sensor
Finer pixels (2.4µm vs 4.63µm)
-45% more resolution
Uncooled
Mono vs color
Specifications
| Specification | ZWO ASI178MM | ZWO ASI294MC Air |
|---|---|---|
| Sensor | ||
| Type | dedicated | dedicated |
| Sensor | Sony IMX178 | Sony IMX294 |
| Sensor tech | CMOS | CMOS |
| Format | 1/1.8" | 4/3" |
| Sensor size | 7.4×4.9mm | 19.1×13.0mm |
| Diagonal | 8.9mm | 23.2mm |
| Pixel size | 2.40µm | 4.63µm |
| Resolution | 3096×2080 | 4144×2822 |
| Megapixels | 6.4MP | 11.7MP |
| Color | No | Yes |
| Cooling | ||
| Cooled | No | Yes |
| Performance | ||
| Full well | 15000e⁻ | 66000e⁻ |
| Peak QE | 81% | 75% |
Advantages of ZWO ASI178MM
- Finer sampling at 2.4µm pixels
- Mono sensor — ideal for narrowband and LRGB
Advantages of ZWO ASI294MC Air
- Larger sensor (23.2mm vs 8.9mm diagonal) — wider field
- Larger pixels — better low-light per-pixel sensitivity
- Higher resolution (11.7MP vs 6.4MP)
- Regulated cooling for long exposures
- One-shot color — simpler workflow
Best for — ZWO ASI178MM
- Longer focal lengths — tighter framing on small targets
- Planetary and lunar high-resolution imaging
- Narrowband and LRGB workflows
Best for — ZWO ASI294MC Air
- Balanced field for most refractors
- Fast, low-noise deep-sky at short focal lengths
- Long-exposure deep-sky under any sky
- One-shot color — quick results, less processing
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 ASI294MC Air — 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 — recommended user
A strong fit for photographers stepping into astro pairing with longer focal lengths where framing is tight.
ZWO ASI294MC Air — recommended user
A strong fit for dedicated deep-sky imagers pairing with a broad range of focal lengths.