You write a movie three times, as the saying goes. Once when you write the screenplay, once again when you shoot the film, and finally again in the editing room. And I'm not talking about actual screenplay rewrites. I'm talking about the fundamental creation of the film. The construction of it's DNA. But what does this mean?
Well, if you've ever made a film, you know what I'm talking about. But in case you haven't, it basically boils down to this. You write one film in your head and in your mind's eye it's perfect in every way. That's the first version. The screenplay. Then you go to make it.
And when you cast it, you discover that the actor in front of you is better or different than the one you had in your head when you were writing it, so it changes there. Then you find a location that doesn't match what's written, but it's amazing in other ways, so you rework the story again. Then while your filming, accidents and mistakes occur. A prop isn't there when you need it. A location becomes suddenly unavailable. An actor's schedule conflicts with the shooting schedule so you have to write the character out of the script before you're done with them. A million things like this happen during production. And all of that improvisational problem solving the director and producers do on set adds up to the second rewrite.
And then you come to post production, the thrid and final rewrite.
If production is a sprint, then post production is a marathon. And it's in this marathon that you discover more happy accidents that change the story. But you also find problems that you didn't or couldn't see during production. All of that improvising that's done on set sometimes causes unbelievable continuity problems that have to be solved in post. Sometimes you didn't get that one shot you needed to tie a scene together. Sometimes you covered the scene from the wrong angle to get the emotional impact you needed to make the scene work. Maybe you shot it with one transition in mind from one scene to another, and now that you put it together, the transition doesn't work.
Problem solving and puzzle building. Lots of it.
And that's for any film. Now add to that the fact that you're making a horror film, where mood, ambience and pacing are arguably more important than in any other genre. And they ALL happen in post.
And here's where you need an editor that's not just good, but good AT HORROR.
In drama, you have to hit a very general area on the target to get a response from an audience. In comedy, you have to hit a specific area on the target to get people to smile, laugh or chuckle. But in horror, you have to hit a friggn' bullseye every time to get the very specific SCARE reaction. There's no room for error and there's no "almost". You either scare your audience or you don't. In comedy, if you miss getting the big laugh, you'll likely still get a chuckle or a smile. But in horror, there's no second place to the scare. It's just like Yoda says, "Do, or Do not. There is no try."
And as a filmmaker, that's brutal. The best horror filmmakers torture themselves in post, making sure that the scare happens at exactly the right frame. And yes, it comes down to frames. If the scare needs to be on frame 3, then it works on frame 3, and falls completely flat on frame 2, frame 5, or anywhere else in the cut. If editing a drama is hand grenades, then cutting horror is precision sniper attack from 2 miles away.
Editing horror is about establishing a rhythm and then breaking it suddenly. Comedy uses the same principal, but the rhythm in comedy is generally in the performance and less in the edit, whereas in horror the rhythm is almost wholly in the edit with much less in the rhythm of the performance.
Much like other members of your team who must have a sense of horror, so too does your editor have to have it. And not only a sense of what's scary, but a working vocabulary of horror, horror films and a litany of personal fears and latent childhood terrors to draw from. It doesn't matter a lick how good their resume is, if they don't have a fundamental sense of what is scary.
Because, believe it or not, you can get the script right, the production right, and then fail miserably in post production, if you're not extremely careful. And in horror, that last rewrite in the editing room is the most important draft of all.
Gaudium per atrox.