ASI2400MC Pro back focus
ZWO specify “Back Focus Distance 17.5mm”. That is measured to the camera's own front face, with no adapters fitted.
- Back focus
- 17.5 mm
- Thread
- M54
- Sensor
- 36 × 24 mm
- Pixel size
- 5.94 µm
- Type
- Colour, cooled
Checked against the manufacturer’s documentation in September 2026.
Telescopes
| Telescope | Back focus | Spacers | Sampling | Result |
|---|---|---|---|---|
| 103APO | 55.0 mm | 16.5 mm | 2.19″/px | Exact |
| 185APO | 55.0 mm | 16.5 mm | 1.18″/px | Exact |
| FRA400 | 55.0 mm | 16.5 mm | 4.38″/px | Exact |
| FRA500 | 55.0 mm | 16.5 mm | 3.50″/px | Exact |
| FRA600 | 55.0 mm | 16.5 mm | 2.92″/px | Exact |
| Evostar 100ED | 55.0 mm | 16.5 mm | 1.60″/px | Exact |
| Evostar 120ED | 55.0 mm | 16.5 mm | 1.60″/px | Exact |
| Evostar 80ED | 55.0 mm | 16.5 mm | 2.40″/px | Exact |
| Fluorostar 91 | 60.4 mm | 21.9 mm | 2.84″/px | Exact |
| Gran Turismo 71 | 64.1 mm | 25.6 mm | 3.66″/px | Exact |
| Gran Turismo 81 | 62.1 mm | 23.5 mm | 3.20″/px | Within tolerance |
| Zenithstar 61 | 56.0 mm | 17.5 mm | 4.25″/px | Exact |
| Zenithstar 81 | 60.2 mm | 21.8 mm | 2.74″/px | Within tolerance |