Camera movement is one of the most expressive tools available to a filmmaker. It alters the relationship between the subject and the camera frame, shaping the viewer's perspective of space and time and controlling the delivery of narrative information. As the camera frame orients the viewer within the mise-en-scène , movement of the frame provides the illusion of the viewer journeying through the world of the narrative. The camera height and angle, the distance to a subject, and the composition of a shot may change during camera movement, as the framing travels above, below, around, into, and out of space. Types of camera movement are distinguished by their direction and the equipment used to achieve motion. Although the basic forms of camera movement were in place by the 1920s, the equipment that facilitates camera motion continues to evolve.
The moving camera can function in a variety of ways and, when used in a long take, is uniquely able to depict uninterrupted stretches of time and space. Camera movement may follow objects in transit within the frame, or may act independently; it may reveal offscreen space, or deliberately suppress access to space; it may objectively witness events, or suggest the subjective perspective of a character; it may advance the narrative, develop themes, or create patterns; and it may contribute to kinetic or rhythmic effects. Fluid camera movement within shots sustained for unusually long periods of time can not only serve as an alternative to editing, but can also punctuate changes in narrative action within the shot and participate in formal patterning across the entirety of a film. The film critic André Bazin was one of the great champions of camera movement within long takes, believing that such shots had the potential to record the reality of the world in front of the camera more accurately than sequences constructed through editing.