Filming continuity - Techniques

180 rule

The 180 degrees rule is a filming guideline that participants in a scene should have the same left-right relationship to each other, filming should only take place on one side of this imaginary line. For example if I were to make a war film the audiences viewpoint would be constantly facing southwards - the soldiers walk from left to right to the frontlines and right to left when they return home, creating a continuous sense of direction. This makes sure the audience doesn't get disorientated and allows them to have a greater sense of location in the scene in terms of what may be off screen in some shots (for example shot reverse shots)

The 180 rule can be violated for effect, like in lord of the rings, to cause confusion or to highlight a characters mental instability and show multiple personalities. Gollum stays in the same place throughout the scene but the camera moves, crossing the 180 line, which would confuse the audience. At the beginning of the scene though the viewer can see the camera cross the line, so this helps orientate the viewer and then once again it gains the audiences trust  - it violates the rule for effect.

Match on action

Match on action is an editing technique, to give extra attention to a certain event in the story, in which one shot cuts to another highlighting something important, like a door handle as a door opens or a phone as someone rings. This creates a sense of continuity and creates a 'visual bridge', it portrays a continuous sense of action rather than matching two different things. The audience is so focused on what's happening on screen they fail to notice the editing and are immersed in the drama that's occurring on screen. It shows a more advanced level of filmmaking where the action in the shot needs to be filmed more than once to achieve all the camera angles necessary. It creates a more visually exciting scene for the viewers to watch.  

Shot reverse shot

Shot reverse shot is a continuity editing technique used in conversations or simply characters looking at each other or objects. A shot showing what the character is supposedly looking at (either a point of view or over the shoulder shot) is followed by a reverse angle shot of the character themselves looking at it, or of the other character looking back at them, for example. Shot reverse shot often ties in with the 180° rule to retain continuity by not distorting the audience’s sense of location of the characters in the shots.

30 degree rule

 The 30 degree rule is used by filmmakers with the purpose of creating continuity between different shots within a larger sequence. It states that the camera should move more than 30 degrees between shots of the same subject occurring in sequence. If this rule isn't followed then the film making can look sloppy and unprofessional and can draw the audiences attention  away from the story line to the filming techniques. Its used to create tension and interest the audience as shot types are varied to create a more aesthetically pleasing film.

Rule of Thirds

This suggests that each image should be divided up into nine equal sections (two evenly spaced horizontal lines, two evenly spaced vertical lines) and that important compositional elements should be placed along these lines or their intersections. This technique is useful as it's claimed that placing a subject with these points creates more tension and interest in what's on screen that simply placing the subject in the centre of the screen. In most "people shots", the main line if interest is the line going through the eyes and they are to the left or right of the screen (1/3 or 2/3 - vertical).