FOCAS instrument parameters
Since 2003 September, read noise has been reduced to be almost half from the old setting. This requires longer readout time. Note also that the gain has changed slightly.
| Detectors | 2 2K x 4K 3-side buttable CCDs (MIT) |
| Pixel size | 15 um |
| Pixel scale | 0.104'' |
| Field of view | 6' (circular) |
| Gain | 2.1 e-/ADU for both |
| Dark current | < 0.1 e-/s |
| Read noise | 4 e- rms |
| Saturation level | 40 000 e- |
| Readout time | 166 s (whole CCD area, no binning) |
| Min. exposure time | 0.5 s (3%) or 1.0 s (1%) |