QHY294M Pro back focus
QHYCCD specify “17.5mm（±0.2）”. Their documentation does not say whether that includes the adapter supplied in the box, so we use it as published.
- Back focus
- 17.5 mm
- Thread
- M42
- Sensor
- 19.28 × 12.95 mm
- Pixel size
- 4.63 µm
- Type
- Mono, cooled
Checked against the manufacturer’s documentation in September 2026.
Where to buy the QHYCCD QHY294M Pro
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Telescopes
| Telescope | Back focus | Spacers | Sampling | Result |
|---|---|---|---|---|
| 103APO | 55.0 mm | 21.0 mm | 1.70″/px | Exact |
| 185APO | 55.0 mm | 21.0 mm | 0.92″/px | Exact |
| FRA400 | 55.0 mm | 21.0 mm | 3.41″/px | Exact |
| FRA500 | 55.0 mm | 21.0 mm | 2.73″/px | Exact |
| FRA600 | 55.0 mm | 21.0 mm | 2.27″/px | Exact |
| Evolux 62ED | 55.0 mm | 21.0 mm | 2.65″/px | Exact |
| Evolux 82ED | 55.0 mm | 21.0 mm | 2.00″/px | Exact |
| Evostar 100ED | 55.0 mm | 21.0 mm | 1.25″/px | Exact |
| Evostar 120ED | 55.0 mm | 21.0 mm | 1.25″/px | Exact |
| Evostar 80ED | 55.0 mm | 21.0 mm | 1.87″/px | Exact |
| Fluorostar 91 | 60.4 mm | 26.4 mm | 2.21″/px | Exact |
| Gran Turismo 71 | 64.1 mm | 30.1 mm | 2.85″/px | Exact |
| Gran Turismo 81 | 62.1 mm | 28.1 mm | 2.50″/px | Exact |
| Zenithstar 61 | 56.0 mm | 22.0 mm | 3.32″/px | Exact |
| Zenithstar 81 | 60.2 mm | 26.2 mm | 2.14″/px | Exact |