I was watching this week’s Helix, and was struck by how the director decided to use depth of field. Depth of Field is a photography term that refers to how much of the image is in focus. If your aperture is low, you have your iris wide open and only a thin layer of the image in front of the camera will be in focus. If your aperture is high, your iris is closed up and almost everything in the picture will be in focus.
For example, the image above. I need to re-take this picture with my aperture higher, because right now the cat is in focus but the tea set and mouse are fuzzy. I wanted the background to be fuzzy, but all of my subjects should be clear.
If you watch this week’s Helix, look for the scene when Alan and Doreen are talking. They’re standing next to each other, and the camera is positioned at Alan’s shoulder so he is in the foreground and she is in the background. When Doreen is talking at the beginning of the scene, the focus remains on Alan and Doreen is just a moving set of blobs in the background. What the director is telling you here is that Alan isn’t hearing Doreen. As far as he’s concerned, she’s not a part of the conversation. Later, the focus shifts to Doreen and you know that now Alan is hearing her. It’s a fascinating technique, and I wonder if it came from the script or was purely the director.