The human eye moves around a room or watches a scene based on leading lines and points of focus. The art of capturing the eye and encouraging its movement in a specific direction is done through composition. There are many types of composition like “L”, leading lines, rectangles, spirals, etc. The study of these forms is typically taught using the rule of thirds, or the golden rule section or ratio.
The cinematographer is well equipped to use these various techniques, but he first must learn what the director is trying to accomplish with the actors as they rehearse or block out their movements. The director will try to create emotional energy within the scene and shift the power between characters. It’s the cinematographer’s job to capture that engagement by racking focus, using a crane, or creating movement with a dolly. The goal of the set up is to help the audience feel and understand what the actors are emoting.
The more actors on set, the more difficult the staging of the shot becomes. The simplest way for the director to capture the essence of the scene and leverage the ability of his cinematographer is to block the actors in groupings of triangles. This can be done by height, distance from the camera, or with three various groupings.
In “The Proposal”, during the engagement announcement scene, the cinematographer uses three groupings of actors (orange boxes of people grouped in a triangle with red lines) with one close to the camera, the next mid way, and the last group farther away. In the last grouping, the actors were grouped in a mini-triangle (blue lines) by the director.
Three-shots can easily be turned into triangle blocking based on distance from camera, actor height, and relative position if one actor stands while others sit. Sometimes the director uses a momentary triangle, as someone walks past in the foreground or background, to break up the obviousness of the blocking.
While still shots might reveal various compositions utilizing triangles, motion pictures will many times interrupt the posing aspect that the composition might encourage with movement. A cinematographer may also choose to rack focus between points of the triangle to create more eye movement.