Any great editor follows this basic rule every single time he or she makes a cut. In fact, it’s the very first rule to consider when making a movie edit appear ‘invisible’ and help the story flow.
The Basic Rule
Here it is: There absolutely must be a reason for the cut (unless you’re deliberately using experimental editing techniques to convey something about the action on set and/or a character’s relation to something). A video editor must be able to use his or her aesthetic perceptions in order to make a cut flow seamlessly with the emotions conveyed in the scene and the story being played out.
Cutting
Cuts may be used for narrative reasons to highlight a specific action taking place, a character’s response and/or expression, or cutaways that are relevant to the action and/ or scene. Cuts may also be used in a kinetic sense--to shorten static shots (shots that stay on an action and/ or subject(s) for a substantial amount of time).
Let’s imagine a wide shot of a scene in a high school hallway between changing classes. Kids are crowding the hall. A young couple leans against a locker, exchanging flirtatious behavior. A teacher storms into frame from around the corner. Then, there’s a sloppy-looking kid carelessly tripping over his shoelaces, walking up from the background.
If the editor chose to keep this shot without any cuts (and/or cut aways), the viewers may not understand the relevance or importance of the action going on, and this may suggest, naturally, everything may be relevant to the scene.
A shot like this, considering one of the subjects/ actions is important--at this moment for narrative reasons--calls for a cut. Depending on the narrative reason (story), the cut may go to the couple, the teacher approaching the couple, and/or the sloppy-looking kid. However, in this particular example, since a few things are going on at the same time, let’s imagine all these actions are taking quite some time to play out. The viewers may lose interest in what’s going on, and therefore, because of this, the editor may chose to cut based on kinetic reasons. Where to cut to, again, depends on the narrative reason: a CU (close up) of the sloppy-looking kid’s untied shoe laces; the couple flirting; the teacher’s thunderous steps. Remember: it’s about what happens next that drives the story, thus giving the editor a reason for the cut.