Vince testing the lighting rig with a cue that points all the moving lights at the lighting desk to check they are working and positionally correct. This cue also lights each type of fixture in a different colour so that we can easily identify specific fixtures in the rig.
https://www.youtube.com/watch?v=hSnz2ot6iTU
The camera exposure compensated for the full-white test, which is painfully bright.