There are a lot of tests that might be shot during the checkout period, if the crew is given enough time and money and raw stock, but I will only attempt to describe and discuss the procedures and the reasons for the most common tests that might be shot for a feature film.
Some of these tests might be done by the Camera Assistant alone; others will require the presence of the Director of Photography; still others will require additional crew and cast members.
Try and find out in advance what tests the Director of Photography wants to shoot, and when he or she will be available to shoot them. The list of tests to be done will be different for every job.
Probably the most important ...