How to ensure the consistency of positive and negative films?

At least two cameras should be used when shooting the front and back of the film. According to the principle of axis, the cameras are all on one side of the 180 degree (imaginary) line, and each camera is aimed at an actor. The most commonly used is the over-the-shoulder pat, which implies the existence of the role.

Dialogue scene is an important scene in every type of film, and dialogue conveys important plot information. Over-the-shoulder shooting combined with forehand and backhand shooting is the shooting technique of most filmmakers.

But once the dialogue is too intensive, it will slow down the pace of the movie. Therefore, the shooting techniques in the dialogue scene, whether over-the-shoulder shooting or single shooting, will make the audience feel different information content and emotional connotation.

Dialogue scenes usually have a fixed pattern inherited from Hollywood, which is often called "head-to-head shooting".

A clip called "head-to-head shot" usually shows two people communicating face to face. The camera lens alternately shows everyone, while the other person is absent or can only see part of it. The filmmaker switches from one shot to another according to the dialogue flow and facial reaction of the characters.

Sometimes the angle of view is close to the back of each character, and the shoulder of another character other than the front character is taken as the foreground, which is called over-the-shoulder shooting.