Frame

A video frame is a single still image — one snapshot captured at a specific instant in time. Video is, at its core, a sequence of thousands of individual frames displayed in rapid succession. The human brain, through a perceptual phenomenon historically called "persistence of vision" and more accurately understood as the phi phenomenon and beta movement, interprets this rapid sequence of still images as continuous, fluid motion. At 24 frames per second (the standard for cinema), the brain receives 24 discrete images every second and perceives them as unbroken movement. At higher frame rates, motion becomes smoother; at lower rates, motion begins to look choppy.

The individual frame is the fundamental unit of digital video production. Editors work with frames as their smallest unit of time when trimming clips — adding or removing a single frame (typically between 1/24 and 1/60 of a second) can change the timing of an edit from barely perceptible to jarring. Visual effects artists work frame-by-frame when compositing or rotoscoping. Color graders can theoretically apply different color treatments to individual frames, though they almost never do. Quality issues — compression artifacts, camera sensor noise, focus issues — are visible at the frame level and become apparent when footage is studied frame by frame.

The resolution of a frame is described by its pixel dimensions: 1920×1080 for Full HD (1080p), 3840×2160 for 4K UHD, and so on. A higher-resolution frame contains more pixels, allowing for sharper images and more headroom for post-production cropping and reframing. The aspect ratio of a frame — the proportional relationship between width and height — determines the shape of every image in the video. Frame composition, the arrangement of subjects and space within the frame's edges, is one of the primary tools cinematographers use to control what the viewer sees, what they focus on, and what emotional response they have to the image.