the 180 degree rule

This schematic shows the axis between two characters and the 180° arc on which cameras may be positioned (green). When cutting from the green arc to the red arc, the characters switch places on the screen.


In the example of a dialogue, if Alice is on the left and Bob is on the right, then *Alice should be facing right at all times, even when Bob is off the edge of the *frame, and Bob should always be facing left. Shifting to the other side of the characters on a cut, so that Bob is now on the left side and Alice is on the right, will disorient the viewer, and break the flow of the scene.

In the example of an action scene, such as a car chase, if a vehicle leaves the right side of the frame in one shot, it should enter from the left side of the frame in the next shot. Leaving from the right and entering from the right will create a similar sense of disorientation as in the dialogue example.

-Problems caused and solutions-

Avoiding crossing the line is a problem that those learning filmcraft can struggle with. In the above example with the car chase, a possible solution is to begin the second cut with the car driving into frame from the "wrong" side. Although this may wrong in the geographic sense on set, it looks more natural to the viewer. Another possibility is to insert a "buffer shot" of the subject head-on (or from behind) to help the viewer understand the camera movement.

-FROM Wikipedia


-ABOUT 180 degree rule-

The 180° rule is a basic film editing guideline that states that two characters (or other elements) in the same scene should always have the same left/right relationship to each other. If the camera passes over the imaginary axis connecting the two subjects, it is called crossing the line. The new shot, from the opposite side, is known as a reverse angle.


During the discussion of 180 degree in the tutorial, i was actually a bit confused at that time. Becasue i sometimes didn't find the image was strange. (when we were watching the vedio of last year's students' works) Therefore i checked online , trying to search for some more actual pictures and do some excercise with my
friends. lol

Apparently it works! And it's pretty clear to understand by doing in a small group of friends.

*Useful tips (according to Paul): Focus on one side of two people's 'shoulder', and don't go furthur to the other shoulder.