While set design is often the obvious choice for establishing geographic space in film, using shallow depth of field and careful blocking can also show the viewer where one space ends and the other begins.
In this scene from his 2012 film The Master, Paul Thomas Anderson uses meticulously placed characters and a shallow depth of field to separate the in-group of the Cause’s meeting from an inquisitive intruder. The scene begins after the woman in blue regains consciousness after going through “processing”–a hypnosis-like interview–with Lancaster Dodd (Philip Seymour Hoffman). As Dodd debriefs her on her experience, the camera has an extremely shallow depth-of-field and focuses primarily on the two characters. Furthermore, every other character is either out-of-focus or partially obscured by out-of-focus objects. At 0:18, for instance, even though there are two other people on the couch with the woman, one is partially covered up by red clothing, and the other is behind the arm of a couch and a bouquet of flowers. At this stage in the conversation, Dodd and the woman are the two main points of focus. Anderson blocks his characters and places his cameras to force us to focus on them while being aware of the space they are establishing.
Anderson reveals the intruder at 0:27. He is obscured by Dodd’s shoulder. Even though he is in focus, we do not feel that he is in the group to which we should be paying attention. He says, “excuse me,” and the scene immediately cuts to the perfectly in-focus shot of Dodd thereby closing the intruder out. At 0:37, we see the intruder again–this time over Dodd’s right shoulder. Anderson is establishing that Dodd’s shoulders mark the edge of the group and the edge of the space. Anderson almost lets the intruder in at 0:57 when he says “excuse me” again. Dodd moves his blurry left shoulder and, just as the intruder is about to be completely unobscured, the scene cuts back to the in-focus shot of Dodd.
At 1:23, Dodd finally acknowledges the intruder and nearly moves out of frame to include him into the in-group’s discussion, but an out-of-focus lamp and Dodd’s wife’s shoulder still stand in his way. The camera almost assumes the intruder’s point-of-view and shows that, in fact, Dodd’s shoulder is the edge of the space. The out-of-focus couch and Dodd’s awkward posture show that the Cause’s conversation begins and ends with him.
After a few minutes of arguing, Dodd stands up to fully engage the intruder. At 3:11, Dodd’s wife’s blurry head moves out of frame and leaves nothing standing the intruder’s way. When the scene cuts back to Dodd, his wife’s out-of-focus head obscures part of his body thereby protecting him from outsiders.
At 4:57, Freddie Quell (Joaquin Phoenix) throws food at the intruder from behind the out-of-focus couch. He is the first and only character to physically move from the in-group to the out-group. This proves to be a central theme in this film.