  We describe the commissioning of a system which has been built to investigate
optimal operation of CCDs for the LSST telescope. The test system is designed
for low vibration, high stability operation and is capable of illuminating a
detector in flat-field, projected spot, projected pattern and Fe-55
configurations. We compare and describe some considerations when choosing a
gain calibration method for CCDs which exhibit the brighter-fatter effect. An
optimisation study on a prototype device of gain and full well with varying
back substrate bias and gate clock levels is presented.
