The stage is set, but before you start to roll camera, you and your team need to know what the actors will be doing and where they'll be positioned. This step is called blocking, and, fair warning, blocking can be one of the most stressful parts of the shoot. We'll be going over what to do before you shoot, as well as handling changes while you shoot. If you listen to your actors, take advice from your director of photography, and follow a plan, it'll be easier to focus on telling a great story.
The first consideration should be all of your on-camera resources. Pretend the lights, camera, and crew don't exist and think about the scene as if it's happening in real life. Talk with your actors and have them act out the scene with no direction from you. Actors are creative people and they want to sell a believable performance. Are they sitting or standing? Note how close together they are, and when and where they move. Try not to critique their delivery yet. Just watch their movements and how much of the set they occupy. Adjust the set so that it compliments your actors. For example, if your star needs to pick up a photo frame to reminisce on a lost love, the photo will need to be in a place where your actor can easily get to it.
At this point, you'll want to talk with your director of photography, or DP, about how to work the camera into the scene. The DP is the person who is in charge of making sure the camera is where it needs to be and set up such that you'll get the shots you want. If you have a storyboard or a shot list, go through the scene with the actors and DP to make sure what the actors are doing can be captured how you want it. Move your actors around the set as if they're pieces on a chess board. Place markers on the floor where actors should be standing or where they'll need to move. Consistency is key. If your actors are hitting different marks every take, your DP will never get the shot they want as the camera won't be able to predict where action will take place.
As your blocking, ask yourself why you're composing the shot the way you are. Do you need one character to appear dominating over another? Make sure the dominating character is standing while the meek character is sitting. Are our eyes supposed to be on the background? Push your actor to the right or left third of the frame. Remember that when you're setting up your shots, you're maniuplating the orientation of the viewer. Even if your character is walking right to left in the room, by changing to a reverse angle, you may flip the viewer's orientation so that the actor appears to be moving left to right. It's important to think about how the shots will piece together in the editing room so that a viewer can internalize the stage you're setting.
iv. Finally, make sure to have someone take notes as to how the scene should unfold. You can do this by writing in the margins if your script, or drawing diagrams of the floor plan. This person is typically referred to as the script supervisor, and we'll come back to that role in a bit.
You've surely agonized over your shot list and storyboard, making sure every shot has a reason for being exactly as you've planned. Having your actor stare directly into the lens will have a drastically different feel than having them stare six inches to the right. Having two characters sitting next to each other at a dining table might be romantic, while having them sitting across from each other could feel adversarial. Actors will "get in the moment" while acting, and may do things that feel natural to them, but that may be contradictory to your vision. It's important that they do what's natural to sell the performance, but stay on top of them with regard to blocking. If they are instant on changing their positioning, be respectful of their opinion. There's nothing wrong with altering the camera setup to accommodate their performance as long as it's appropriate for the scene. That's your call to make.
While shooting, you should be in constant communication with your DP. Sometimes getting a shot means making adjustments to the camera setup and you'll need to make spur of the moment decisions. Do you bring your actors closer together to make sure they're both in focus, or do you change out the lens and reposition the camera? Getting the shot you want may not technically be possible with the your established blocking, and if that's the case, your DP will surely tell you about it.
Remember the script supervisor? Since you're likely adjust the blocking on the fly, it's important that you have the script supervisor's notes so he or she can keep an eye out for continuity errors. Continuity is the concept that everything appears to be where they should be between shots. For example, if I have an actor take a sip of coffee with their right hand, but in the reverse shot, they place the coffee cup down on the table with their left hand, continuity has been broken. Your script supervisor's job is to read through the script as it's being shot and make sure the actors are delivering the correct lines at the right time. Additionally, they watch the action and take notes on where the actors are in relation to everything else in the scene.
Keep in mind, however, that it's OK to cheat. You'll often hear directors telling their actors to cheat to the right or left, or cheat lights around in the scene. That's because the only thing that matters is what the camera sees and what's believable to the viewer. Once your camera is in place, you should feel free to make adjustments to the actors and props. This is most common when the alternative is to move the camera and lights. For example, if you're shooting over the shoulder of one actor to a closeup on another, and you want to have the closer actor's shoulder and head obscure more of the frame, you can either move your camera to adjust the perspective, or you can have the actor move further into the frame. Your audience will never notice that the actor is positioned differently and you won't have to spend the time moving a bulky camera setup.
If you've taken the time to block your shots before you shoot, and monitored continuity throughout, then you've set yourself up for a smooth shoot. Your editor will thank you for the attention to detail, and your viewers won't have time to think about your work as they'll be sucked into y story.