Sometimes it’s what’s outside your focus that you should pay attention to.
“Negative Space” is not the title of a Luc-Besson-produced Paul W.S. Anderson film – though it should be – but rather a cinematic term that refers to, basically, everything in a film frame that isn’t the subject. A stark example would be in Alfonso Cuaron’s Gravity when George Clooney’s character is drifting away into space. Here, Clooney is the subject and the negative space is actual space. A less obvious example would be any scene in which a character is walking down a crowded New York City sidewalk; the character is the focus, and all the other people, buildings, and assorted activity going on around them constitutes the negative space.
As these two examples illustrate, negative space can be a physical space – like outer space, a field, the ocean et cetera – or it can be composed of other people and things. Either way the basic purpose is the same: to draw your attention to the subject. But notice the use of “basic” in that sentence; once a filmmaker gets comfortable with negative space, they discover there are many more uses for the effect, from comedic to suspense-building and all stops in between.
In the following video from James Hayes of Film in the Making, a more thorough explanation of negative space is provided, along with examples of the many different ways filmmakers have made use of it to inform our perception of subject. The result is an eye-opening look at the things we maybe don’t see in a frame but that still have a massive impact on the emotional effectiveness of a film.