What is the name of the black-and-white sign used to count down before the camera starts when shooting movies and TV?

A small wooden board with the number of times, scenes, director, film title, film company and other information written on it. One end can be opened and closed to make a clear sound, so that the sound and picture are synchronized when editing.

The inventor of the first slate in film history may be Frank Thring, who was the director of Eftee Film Studio in Melbourne, Australia in the 1920s.

Movies are made up of many shots, and each movie usually has hundreds or even thousands of shots. The scene and content in the film are very complicated. When shooting a movie, it is impossible to follow the sequence of the plots, but to shoot according to the scenes, such as shooting the location first, then shooting the scene on the set, or shooting the scene in summer first, then shooting the scene in winter, even if it is the same winter scene, some plots happen in front of the story and some plots happen in the back. In order to ensure the quality, some shots have to be shot several times. After months of hard work, I brought back a lot of film. How can we piece it together into a complete movie? If there is no obvious mark on the film, it will bring great trouble to the later editing work.

In the long-term practice, filmmakers have found a good way. They used a small board with black and white stripes, which simply wrote the relevant contents of the film to be filmed. Before each shot, take this "board" as the mark of this shot. This step is called "clapping your hands" or "filming" in the jargon of the film industry. In this way, there is a slate shot at the beginning of each film. In post-production, as long as the staff see this mark, they will know which film, scene and shot this film is, which is easy to identify. In addition, clothing, make-up, props and other staff can also use this to avoid flaws in the details of shots taken at different times, thus avoiding mistakes.