180 Degrees Rule

The 180 degree rule is very important when filming. All coverage should be shot from one side of an imaginary line that connects two people that are speaking to each other so that when editing the sequence together the characters are on the right side. For example if you are filming a conversation with over shoulder shots the camera the camera must stay to one side of the line if this does not happen then it will look like the characters are looking in the same direction.

If the 180 degrees rule is followed then this is what it should look like below, the camera is on both of the characters right shoulders to make sure the characters are looking the right way.

 

This is an image, below, of the 180 degrees rule being broken, it looks like both of the characters have swapped places and talking from the same side. This happens when the camera is on both of the characters left shoulder. The rule can be broken sometimes such as in the shining to create an uneasy feeling for the audience.