Our colleagues Sophia, Katharina and Lucia have tested all our CCD cameras today. This includes shots that provide the pixel noise and give information about the quality of the readout electronics. Other shots provide the signal level at different exposure times to check the linearity of the sensitivity. These tests are important for later analysis of images taken with these cameras. The photo shows the colleagues at work. In the process, two older students snuck in who apparently had to repeat classes more than once.