Film, video, animation — any medium unfolding in time, not static. Duration and rhythm are the material itself, unlike photography or painting.
Duration is your material. This fundamentally distinguishes time-based media from anything static. Film, video, animation—they exist only in flow. You can look at a photograph for as long as you want. A film imposes its rhythm on you. You sit in the cinema, and the images move at 24 frames per second. You cannot watch slower. This is the condition of the medium.
On set or in the edit, you therefore work not only with composition and color—you juggle with time. One cut lasts three seconds, another twenty frames. The music starts here and ends there. The viewer experiences not a single piece of information, but a flow of information that shapes their understanding and emotions at a specific speed. If you shorten a cut by two frames, the tension changes. If you hold a shot longer, it becomes significant—or boring. This is the material you shape.
Time-based media necessitate decisions about rhythm. A slow zoom over three seconds feels different than the same zoom in one second—not quantitatively slower, but qualitatively different. The viewer becomes a witness to a process rather than a moment. This is why DoPs and editors constantly work with time: How long do you hold on a close-up? When do you cut away? When do you let it breathe? These decisions are not aesthetic—they are structural. They determine how the film functions.
This also distinguishes time-based media from interactive media—there, the user determines the duration, not the viewer. Film and video completely relinquish control over time to you. This is the power of the medium and its cruelty at the same time. You cannot see a scene faster or slower than the director intended. The rhythm is non-negotiable—it is the statement.