Tiffen T5 Blue-Screen Viewing Filter #5 T5CVF Grauglas
This Tiffen Blue Screen Viewing Glass has a Blue 25 Lens and enables the gaffer or DP to determine if a blue screen is evenly lit. Use contrast viewers to judge relative highlight and shadow densities. There are viewers for black-and-white film, as well as various viewer densities for color film. A darker viewer is used for slower film speeds, where you would tend to use brighter lighting; Faster film, which can be used in dimmer settings would require a lighter viewer.