Following the 180-degree rule
The 180-degree rule is a critical guideline for how scenes are shot in a film or video. When you watch a movie in which two characters are speaking and the cut moves from one to the other, you’re likely seeing the 180-degree rule in action: It establishes the spatial relationship between characters or objects within a scene — specifically, when the scene cuts between shots of them. Most viewers are una- ware of the 180-degree rule when it’s followed; but when it isn’t, viewers can become disoriented or confused about where characters are standing or sitting in relation to each other.
To use the 180-degree rule to construct a scene, imagine a straight line running down the middle of the characters, as shown in Figure 7-1. To avoid disorienting the audience, choose one side of the 180-degree line on which to shoot all your shots, and don’t cross the line. Understanding this concept can be confusing, so we walk you through an example.
line of the 180-degree rule.
Rather than show each actor individually, such as in the bouncing-ball example, you can use the popular Hollywood technique known as the over-the shoulder shot. For a shot of the child in the example looking up at his mother, you place the camera over her left shoulder and aim it at the child so that part of her left shoulder and hair frame the shot of his face.
Cut back to the mother looking crossly at her child. If you place the camera over his right shoulder, pointing up at the mother, who is towering over him, his right shoulder and hair frame the shot of his mother looking cross. Then you cut back to the first shot over her left shoulder, of the child looking remorseful.
In this example, you stay on one side of the line, over the mother’s left shoulder and over the child’s right shoulder. If we had moved from her left to his left, we would have crossed the line and confused the audience, because they wouldn’t know where the characters were standing in relation to each other.
In another example, you see a shot of a train flying down the tracks, moving from right to left in the frame. Cut to a person waiting for the train, and then cut back to the same train, except that now you’ve crossed the tracks and you’re shooting from an angle on the other side. The train is now moving from left to right! Your brain believes that it’s another train, heading directly for the first train, and sud- denly you’ve made a disaster film!
The 180-degree rule has one exception: If the camera is moving, you’re allowed to cross the imaginary line if the shot itself moves across it. Then the audience will understand why you switch sides in the next shot.