In photography, wherever a still or movie camera is used there is always a need to measure the light value. A reflective light metering device has been incorporated into lights for popular photography including
video camcorders and
professional cameras, the the reflective type light meters sense the light, reflected back from the subject, and in many cameras some or all of the camera settings are then made automatically. The reflective light meter determines the amount of light reflected off the subject in order to increase the output of the camera's onboard light in low light and to decrease the output in bright light. Incident type light meters are used in cinematography which requires detailed accurate measurement and close control of lighting due to the high standards sought and the limitations of
photographic film. In incident light meters the light sensitive element is typically placed behind a translucent diffuser to provide a relatively broad directivity pattern in comparison to the reflective type which is typically as directional as the
camera lens angle.
