Using the 18 per cent grey card
Perhaps the most important use of the grey card is as a messenger to the processing laboratory. By adjusting the brightness, and indeed the colour, of the grey card then photographing it before you shoot a scene you have, possibly, the most powerful communication tool in cinematography.
In order to use this tool you must first tell the processing laboratory you need them to participate. You can do this in three ways:
1 Before shooting, explain to the laboratory that, at the beginning of every day’s rushes, there will be a grey card and would they, please, always grade the following scenes to that grey card. Tell them that when you want the grading changed you will put a new card on.
2 When ...