A discussion of very short and very long films outside of feature length, with an emphasis on film. Avant-garde filmmaking, excluded but also liberated from the requirements of mainstream exhibition and distribution, have usually ignored the two-hours standard. Mainstream audiences often find that short independent films are too long because they are accustomed to the narrative structures of the mainstream.

Independent filmmakers who make long films often intend them for specific events, or use the extended length to reveal to the audience that the passivity with which they attend mainstream films will not be rewarding in these screenings, goading them to engage more intensely with the visuals and the form of the film that they take for granted. Diary films that span many years can also be viewed as long single film, where the expense of long lengths of film are countered by shooting on a cheap format.

Short films were once programmed as disposable warm-ups for features, but the power of the TV ad should assure the viewer that shorts can have considerable influence. The labour-intensive nature of animation predisposes it towards the short, and other filmmakers similarly interested in the frame as a visual unit tend to produce dense short films.