180 Degree Line

How to establish "the line"

Think of a stage. The audience only see the action from the audience side. This is the same in film. This is so the audience does not get confused and wonder why the actor they first saw on the right hand side of the scene is now on the left hand side or vice versa. This is known as "crossing the line".

Using Transition Shots to cross the line

Using a transition shot then changes where the line is. It pivots the line to another line by turning the sightline of a character to a new area or person within the shot.

Another transition shot is for the character to cross their own line during the shot. Or the camera itself may cross the line with a pan also during the shot which creates the new line.

Another way also of changing where the line is, is by using a cutaway. For example a close up of a character turning their head and as their eyes follow off screen when you cut to the next shot using the previous setup you can re-establish a new line because the viewer is expecting the characters to be in different places.

You can cross the line during the shot but NOT BETWEEN THEM!!!