180 degree rule.

180 degree rule

This is the 180 degree rule. This is where the camera can only stay on one side of the action, if it were to break the rule, the audience would feel disorientated. Sometimes the directore purposely breaks this rule, for example in 'The Shining' Jack Nicholson is talking to another character in the bathroom, however when the director breaks the 180 degree rule we understand that he is actually talking to himself.