Answer:
The 180-degree rule is a guideline used in cinematography that defines how two characters in a scene should maintain the same left/right relationship to one another. It helps to create a sense of continuity and spatial orientation for the audience.
According to the 180-degree rule, an imaginary line called the "axis of action" is established between the two characters or subjects in the scene. The camera is then positioned on one side of this line and stays there throughout the scene. This ensures that the characters always appear to be looking in the same direction and that their positions relative to each other remain consistent.
By adhering to the 180-degree rule, filmmakers can avoid confusing the audience with sudden shifts in character positioning or eyelines. This rule helps maintain visual coherence and allows the audience to understand the spatial relationship between characters.