The Real Reason Horror Movies Have So Many Blurry Shots
One of the most unique things about the horror genre is the way horror filmmaking works to scare an audience. While many films agonize over trying to make an audience cry, laugh, and consider some philosophical message, horror pics have spent decades perfecting ways to make their audiences scream. We can pick up on some of the more obvious techniques in these movies: jump scares that send us leaping up out of our seats, sinister soundtracks that draw out the tension of some fast-approaching danger, and the entire found-footage genre that tries to trick us into believing what we are seeing on the screen could be real.
These are the more obvious methods horror films use to get under our skin, but what about the more subliminal techniques Hollywood has up its sleeve? There's one such trick, as pointed out by Insider, that has become incredibly popular in recent memory. Once you see it explained, you'll start recognizing it in every new horror movie you watch.
A blurry shot can be impactful to a horror movie
The technique in question relies on understanding the psychological effects of focal length in filmmaking (also briefly touched on by PremiumBeat). In most films, a shallow depth of field forces the camera to focus on only part of the image. The shot emphasizes the subject and blurs what's both behind and around it. While the shallow focus is normally used to draw our eye to a specific character or object in each scene, in horror movies, this technique is flipped on its head. Now, the emphasis is on the blurred images, and how those images make the audience uneasy.
A notable example of this technique can be seen in 2008's "The Strangers." In one particularly tense scene (via YouTube), Glenn Howerton's character, Mike, enters the home of the protagonists, unaware that danger is lurking nearby. As Mike movies through the house, we cut to see his face. Behind him and just out of focus is one of the killers, who is blurry but still clear enough to know he's about to try and kill him.
Now you see me, now you... only kinda see me
Additionally, blurry shots in horror confuse the viewer as to where they should be looking. When a character's background is dark and out of focus, it signals to the audience that danger could be lurking right behind them. The audience is forced to strain their eyes searching that of the out-of-focus portion of the shot. As shallow focus shots are a staple of nearly every major motion picture, the way horror manipulates those shots to send doubt and fear into our minds is nothing short of genius.
In 2016's "The Conjuring 2," Ed Warren (Patrick Wilson) interviews a possessed girl, Janet (Madison Wolfe). However, the only way to make the spirit inside of her speak is for Ed to turn away from Janet, which in turn affects the composition of the shot (via YouTube). As soon as Ed shifts, the camera focuses on the paranormal investigator, while the young girl is blurred but still visibly contorts and her voice deepens, signaling to viewers that the entity inside her has emerged. Crucially, we never clearly see what Janet really looks like when she is possessed in this moment.