Excellent - thank you - there are many videos - the following was useful to me - shows how a cameras characteristics are modelled (which takes about 8 minutes) then the optimal exposure and gain settings are determined - by aiming a shot at a dark place in the sky and selecting Histogram -> Brain - selecting unity gain and then measure - which takes a few minutes and then you are done.
https://www.youtube.com/watch?v=AidhxeAJJ3s