In September the new CCD and camera was installed and commissioned at the telescope. The main objective of the change was to increase the stability of the PSF across the field, and reduce the degradation in the PSF due to charge diffusion of the CCD.
The new CCD and camera combination did show a significant improvement in image quality across the field of view, reaching close to the practical limit of a 2 pixel resolution obtained in data taken during the commissioning. An increase in the throughput of the system compared to the old CCD and camera is measured below 4000 Å, but the efficiency at all other wavelengths have decrease by between 15 and 20%, which is well below what was expected. Also an increase in the level of fringing by a factor of 2 in the red part of the spectrum was observed.
From an analysis of the commissioning data it was conclude that most likely the coating of the new optics were the problem. Indeed, the manufacturers found that they had made a mistake in preparing the optics for the camera. Currently we are looking at options how to improve the situation in the best way.