In cinematography, full frame refers to an image area (today most commonly on a digital sensor) that is the same size as that used by a 35mm still camera.^[1] Still cameras run the film horizontally behind the lens, whereas standard 35mm motion-picture cameras run the film vertically. Thus a 35mm still camera's image is significantly larger than that of a standard 35mm motion-picture camera.

Specialty motion-picture formats have used film running horizontally, notably VistaVision (which produced a "full-frame" image) and Imax.

Historically, most digital cinema cameras have used Super-35-sized (similar to APS-C) sensors,^[2] largely to maintain compatibility with existing lenses and to produce traditional "cinematic" depth of field and field of view.

Full-frame cameras require lenses with larger optics, and produce shallower depth of field than conventional 35mm cinema cameras.^[3]