Film lighting is set to not only illuminate the scene, but to make each actor look his best. Soft, diffused lighting is important for minimizing skin flaws and has been used to lend a dream-like quality to movie stars. The main component of classic film lighting is a three-point lighting system. One light above and in front of the actor, called a key light, is used for general illumination and aimed at the primary actor's face. A fill light is added on the opposite side from the key light to soften or reduce shadows. Fill light is generally softer and/or dimmer than the key light. The third light is placed behind the actor, aiming down from above. This light adds to the viewer's perception of the actor's three-dimensionality and her distance from the background.
A classic example of film noir style is a single, harsh light aimed through a set of horizontal window blinds so the light projects the shadows of the blinds on the actor's face, reducing visibility in favor of creating a dark, brooding mood. The essence of film noir lighting is high-contrast blacks and whites, where the shadows are completely impenetrable to the eye. No fill or backlight is used, leaving shadows in the background. A single, non-diffused light source may be set to a lower intensity than the key light, to create additional shadows formed by the natural hills and valleys of the actors' facial structures.
Low-key lighting minimizes the use of light to create suspense or apprehension. Unlike noir lighting, where the intent is to create stark contrast without a specific focus on actor or background, low-key lighting generally illuminates only one specific portion of the subject and leaves everything else dim or completely dark. This technique is often used in horror and science fiction films.