Lighting is an essential part of filmmaking that influences the audience's emotional reaction. The angle and quality of light provides clues about the scene's time and location. Lighting also impacts the audience's perception of the film's production value. A scene can be lit using available natural light or artificial lights. Different types of lighting like hard, soft, and back lights are used to achieve different aesthetic effects and influence how the audience views characters. Professional films typically use a minimum of four light sources, including a key light, fill light, and back light, to properly illuminate subjects.