A
background light is used to illuminate the background area of a
set. The background light will also provide separation between the subject and the background. Many lighting setups follow a
three-point lighting or
four-point lighting setup. Four-point lighting is the same as three-point lighting with the addition of a background light. In a four-point lighting, the background light is placed last and is usually placed directly behind the subject and pointed at the background. By adding a background light to a set, filmmakers can add a sense of depth to shots.