QHY533C back focus
QHYCCD specify “17mm（±0.2）”. Their documentation does not say whether that includes the adapter supplied in the box, so we use it as published.
- Back focus
- 17.0 mm
- Thread
- M42
- Sensor
- 11.31 × 11.31 mm
- Pixel size
- 3.76 µm
- Type
- Colour, cooled
Checked against the manufacturer’s documentation in September 2026.
Where to buy the QHYCCD QHY533C
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Telescopes
| Telescope | Back focus | Spacers | Sampling | Result |
|---|---|---|---|---|
| 103APO | 55.0 mm | 21.5 mm | 1.38″/px | Exact |
| 185APO | 55.0 mm | 21.5 mm | 0.75″/px | Exact |
| FRA400 | 55.0 mm | 21.5 mm | 2.77″/px | Exact |
| FRA500 | 55.0 mm | 21.5 mm | 2.22″/px | Exact |
| FRA600 | 55.0 mm | 21.5 mm | 1.85″/px | Exact |
| Evolux 62ED | 55.0 mm | 21.5 mm | 2.15″/px | Exact |
| Evolux 82ED | 55.0 mm | 21.5 mm | 1.63″/px | Exact |
| Evostar 100ED | 55.0 mm | 21.5 mm | 1.01″/px | Exact |
| Evostar 120ED | 55.0 mm | 21.5 mm | 1.01″/px | Exact |
| Evostar 80ED | 55.0 mm | 21.5 mm | 1.52″/px | Exact |
| Fluorostar 91 | 60.4 mm | 26.9 mm | 1.80″/px | Exact |
| Gran Turismo 71 | 64.1 mm | 30.6 mm | 2.31″/px | Exact |
| Gran Turismo 81 | 62.1 mm | 28.6 mm | 2.03″/px | Exact |
| Zenithstar 61 | 56.0 mm | 22.5 mm | 2.69″/px | Exact |
| Zenithstar 81 | 60.2 mm | 26.7 mm | 1.73″/px | Exact |