Just like the visuals, the story and the characters, editing is part and parcel to a good piece of work. Good editing can make your film more exciting and more dramatic.
It can also, in some cases, make up for a lack of strong visuals. It is one of the final stages of the great balancing act required to make a great film.
When making a short or feature length film with little cash, good editing is valuable. This is the stage where the film moves from being a collection of shots to a single piece.
A good editor must have a sense of pacing, to know when to cut from one shot to another. Just like an angle or a particular frame conveys an idea, so can a single cut. Part of a film’s subtext can be told through editing choices.
Editing also controls the pacing of the film. A slow-paced film could bore the audience, just like one with too many fast cuts may confuse them and pull them out of the movie.
As an example of a film with fast pacing, take a look at The Rock. As you watch it, pay attention to the amount of time the film spends on a single shot. You’ll find it’s only about 5 seconds, give or take. While there are exceptions, for the most part, the film is constantly shifting from shot to shot. This is something that isn’t particularly easy to notice, especially in today’s society, where we are inundated with sound bites and 30 second spots. But the more you pay attention to it, the more you will become attuned to it.
I would also point to Star Wars, especially the sequence at the end, the assault on the Death Star. Notice how the pacing of the editing increases as the action of the story is more tense and action oriented. Shifting the pace of a film can also serves to convey a sense of anxiety or danger.
Bad editing is easy to spot. While I cannot think of an example of one right now, your instincts will tell you when a film is poorly edited or not. Generally, at least for me, if the editing is inappropriately fast during a scene in which a slower pace would be more appropriate, the film becomes somewhat jarring.
To really understand what I mean, I highly recommend that you read the book, “In the Blink of an Eye: A Perspective on Film Editing,” by Walter Murch — the famed editor of dozens of films, including Apocalypse Now, American Graffiti and The Unbearable Lightness of Being. He talks intimately about the editing process and how he approaches the craft. His insights are both educational and thought provoking.