Additional lighting used to supplement the principal light source and brighten shadows cast by the main light and thereby reduces the contrast in a photograph Fill light may be supplied by redirecting light with a card reflector or by using a flash unit, for example
Light that is used to fill in any dark spots or gaps between lights in a overall plot This can also be a light that is used to light scenery, as in the walls of a tall set Most of the lighting will be on the actors and occasionally additional light needs to be added to even out the light between the actors and the scenery