| Unit | Prime-System (2 lens) | Prime-System (3 lens) | RC-System | IR-System | |
|---|---|---|---|---|---|
| Aperture | mm | 3,500 | |||
| Focal Length | mm | 12,195 | 13,761 | 35,000 | 157,500 |
| Central Obscuration | mm ø | 820 | 1,367 | 281.66 | |
| Effective Collecting Area | m² | 9.093 | 8.153 | 8.969* | |
| f/ratio | 1/3.48 | 1/3.93 | 1/10.0 | 1/45 | |
| FOV | mm | 100 | 243 | 300 | 109 |
| arcmin | 28.19 | 60.71 | 29.47 | 2.38 | |
| Scale | "/mm | 16.9 | 15.0 | 5.89 | 1.31 |
| Radius of Field Curvature | mm | Infinite | -3,786 | ||
| Hourangle Range | h | -7 to +7 | |||
* undersized secondary
Image of the 3.5m telescope (399 kB)
Cut through 3.5m building (17 kB)