What is the difference between the so-called background light and the main light in the film lighting?

Lighting is the arrangement of lighting, that is, according to the content and theme of TV programs, some lamps and light blocking tools are selected to produce certain lighting effects in the whole shooting scene. This lighting effect should have four functions:

1. Contrast of illuminance, color temperature and brightness that meet the technical requirements of video recording.

2. To complete the modeling of the image of the screen, it is necessary to change the plane structure of the screen into a visual three-dimensional structure to express the texture, three-dimensional sense and spatial perspective of the object.

3. Use the direction, intensity, softness and tone of light to match the theme and content of TV programs, and help express the emotions and inner world of characters.

4. Form artistic conception or create special artistic effects. Light distribution method, as its name implies, is the method used in light distribution. Because there is no clear classification principle that conforms to the law of TV lighting art, many lighting engineers feel a little vague about the semantics of lighting methods. In the production of TV programs, there are many ways to mention lighting. For example: three-point lighting method, integral lighting method, multi-main lighting method, continuous lighting method, partition lighting method, imitation natural light method, traditional lighting method, night lighting method, virtual lighting method and so on. We believe that these light distribution methods can actually be divided into concrete methods and macro methods. The specific method is to use some skills and means to achieve a specific purpose when lighting a lamp. Such as continuous lighting, district lighting, night lighting, etc. Macro method is a design idea selected from the whole program to achieve an artistic conception or aesthetic effect. In the TV lighting art, the lighting technology as its material support and some specific lighting methods with strong skills are of course important, but the lighting design with aesthetic value is the decisive factor that makes it an "art". The light distribution method discussed in this paper is a macroscopic light distribution method with aesthetic significance. 2. From the macroscopic point of view, or from the aesthetic point of view, there are four light distribution methods: three-point light distribution method, large-plane light distribution method, virtual light distribution method and decorative light distribution method.

1. Three-point light distribution method is a classic light distribution method. It uses the main light, auxiliary light and backlight to distribute the light to the subject, and consciously creates shadows on the subject's face to change its brightness, but the overall tone does not exceed the dynamic range of the camera, and it can clearly distinguish the subject from the background. This light distribution method does not fix the three lights in a certain position in specific use, but determines the position of the main and auxiliary lights according to the face of the subject. In fact, some decorative lights other than the three lights are used to hide or highlight some features. This light distribution method is suitable for a single host, and it is a cheap photographic equipment. With the increasing number of subjects, the lighting effect is difficult to control.

2. The large plane lighting method means that all lights are aimed at the subject and background regardless of priority, so that the surface of the subject and background forms a unified brightness, and the characteristics of the subject and background are not highlighted or concealed, so that the audience can see at a glance. This lighting method is suitable for shooting occasions where the subject's appearance and figure are good or the makeup and clothing are elegant. The advantage is that you can basically drain the light at one time, and you don't have to move any more, so you can get rid of the shadow better. The disadvantage is that the light has no layering and no lasting appeal of light and shadow.