180° line

180° line describes and constrains the spatial relations between objects, objects’ moving direction and camera angle.

Almost all shots have a particular “direction”. For instance, in its simplest form, a single person is moving in a shot. The line along his moving path is the 180° line.

The director should only position her camera on one side of the line. And the editor, namely you, should only use the shots from one side of the line in a continuous sequence. This way, the person is always moving in one direction on screen.

Following this rule makes your video logical and consistent. On the other hand, crossing the line will confuse your audience: is the person walking towards left, or right?

Since not crossing the line is rule #1, a whole chapter is devoted into it. For detailed discussion, go to 180° line rule.

180° line - Video Editing Terms & Glossary

180° line