180 degree rule & shot reverse shot

The 180 degree rule
In class we have been studying different camera angles, and I will be focusing on the 180 degree rule in this post.
In film making, the 180-degree rule is a basic guideline regarding the on-screen spatial relationship between a character and another character or object within a scene.
This rule states that the camera should stay on one side off the imaginary line. This ensures continuity between shots.

If you break the rule in over-the-shoulder shots, it can seem as if the characters are not looking at each other, this can be the case in many Hollywood movies, it is a huge editorial mistake.

This picture shows the relationship of the camera and the 180 degree angle it must keep. The camera can rotate from side to side in the green area and the characters image and positioning will remain the same throughout, where as if the camera were to rotate into the red area the characters position would be opposite and from the wrong angle, so the continuity of the editing would be wrong.

shot reverse shot

Shot reverse shot (or shot/counter-shot) is a camera angle where one character is shown looking at another character (often off-screen), and then the other character is shown looking back at the first character. Since the characters are shown facing in opposite directions, the viewer assumes that they are looking at each other.

The Shot reverse Shot also involves quick cuts and cross editing to work. 

This image is show how the camera is on one characters action / movement, it then shows the second characters action/movement and then refers back to the original characters reaction. This camera angle is used frequently in film and is a good shot to use to portray emotion.