ABSTRACT

Every shot recorded by the camera/recorder has a variation of brightness contained within it. This variation of brightness is the contrast range of the scene. The ratio between the brightest part of the subject and the darkest part is the contrast ratio. The average exterior contrast ratio is approximately 150:1 but it can be as high as 1000:1. Whereas the contrast ratios of everyday locations and interiors can range from 20:1 to 1000:1, a video camera can only record a scene range of approximately 32:1. Peak white (100%) to black level (3.125%) is equivalent to five stops. The contrast range can be extended by compressing the highlights using a non-linear transfer characteristic when translating light into the television signal (see Contrast control, page 70).