Lighting key is a of way describing the kinds of choices filmmakers have make for light a film. Filmmakers use different lighting keys to suggest certain meanings to the target audiences. The lighting key a filmmaker chooses to use in a film will its determine theme or mood.
Low-key lighting is a form of lighting key. It uses shadows and directed pools of light to create atmosphere and suspense. It is often seen in crime or gangster movies. Low-key lighting suggests mystery. Horror movies often use this style of lighting to emphasis the mood of the film. They do this by placing a light above the face or under the face of actors to create a dramatic or distorted effect.
Different styles of lighting can be used effectively in the same movie to convey different moods and events. For example, the filmmaker may introduce low-key lighting to indicate that the hero is in danger.
High contrast lighting can also be used in horror movies. Harsh lines of light combined with dramatic streaks of blackness dominate it. This lighting style tends to use shadows and can look haunting and when it is used well. High contrast lighting suggests a sense of anxiety or confusion. It can also be used to suggest a corrupt world, which haunts and threatens the characters on screen.