What's up, guys?! You know me. I'm that guy. From that thing. You know, that thing? No? Ah well, might as well just give you what you came here for. So you want to know what a director of photography does, huh? Well you're in luck! It's time for this week's "...FOR DUMMIES!"
Like quite a few other crew positions (Producer, Director, etc.) the director of photography's (or DP for short) job stretches out over all three stages of production: preproduction, production, and postproduction. They really don't get any sleep, but who needs sleep?! Let me break it down for you.
Obviously, we start with preproduction. Duh. The DP begins his/her job with discussing the director's vision for the overall film as well as scene by scene. Based on what the director is looking for, the DP determines what exactly is needed for each scene, and, following that, hires a camera crew and organizes and purchases any equipment and supplies that will be needed. When deciding what's needed for each scene, the DP works with many other departments--including sound and lighting--to coordinate production needs. In summary, the DP uses his preproduction time very wisely. He pretty much plans out every shot and gets any and all the tools he'll need to acquire these shots.
After many months of planning, the DP's job moves into production. The most essential thing the DP must do during this step of the process is to coordinate the crew while working closely with the director to make sure every scene and shot is set up to match the director's vision. If the director doesn't get what they want, may Hitchcock have mercy on your soul. Here's where the difficult stuff comes in. For each and every shot, the DP must decide on: the best combination of cameras (oh yeah, filters and lenses, too), the placement of the cameras, what the lighting should look like, AND when the best time would be to shoot. On particularly large films, the DP often oversees several cinematographers who supervise different camera set-ups. He often ALSO manages the photography budget, so the DP is kind of like a part-time production accountant.
Finally we come to postproduction (yeah right, we're not done yet). The first step of the third step of the three-step film production process begins with the DP working with the processing lab to make sure the film retains the color and the mood that he and the director were aiming for. If this part of the process gets screwed up, then a big chunk of all the hard work and planning goes right down the drain. The DP also reviews dailies as well as cuts of the film throughout the editing process. It's important for the DP to participate as a critical eye throughout postproduction.
Alongside the film director, the director of photography has some of the most creative control of the entire crew. They decide what we see and how we're going to see it. Often times, the DP is the person who makes a good film into a film that we'll never forget...
Or they can be the person who absolutely ruins it. Either way, they're really important.