180 degree rule

The 180 degree rule is used as a Continuity Editing Technique. It keeps the action on one side of the camera; this ensures that the characters are grounded compositionally on a particular side of the screen or frame, and keeps them looking at one another when only one character is seen onscreen at a time. The camera must not cross over the axis of action; if it does, it risks giving the impression that the actors' positions in the scene have been reversed - as shown in the picture and video above. Another important technique is Eyeline Match. This goes hand in hand with the 180 degree rule because if the 180 degree rule is broken then the eyeline match is also - the characters will appear to talk to thin air! The Eyeline Match begins with a character looking at something off-screen, followed by a cut to the object or person at which the character is looking. For example, a man is looking off-screen to his left, and then the film cuts to a television that he is watching.