The Collimated Beam Projector is a hardware system to measure the optical transmission of telescopes. I will show how it has been characterized, used to measure the StarDice transmission at the sub-percent level, and lessons for the future LSST CBP.
The measurement of equivalent widths and the measurement of telescope transmission from Bouguer lines will be presented
We will compare flat-fields obtained in 2 bandwidths, and show their good correlation for small scale fluctuations. We will propose a specific deflating technique for spectroscopy.
I will first present the general context of my commissioning work on Run 5 focal plane data performed at CC-IN2P3. I will then focus on studies of the bias frame corrections, which are required for the science image processing: the optimal strategy still remains to be defined and the chosen method will have to be fully implemented in the DM stack.
