Film and Photography

Film is traditionally understood to be the material medium that unites photography and cinematography. Photography and cinema are, together, distinguished from other media by sharing this material [Page 517]basis. In fact, the earliest photographers did not use film, but, rather, glass or polished metal plates, and a modern photographer or cinematographer is increasingly likely to use electronic means of recording rather than film. Nevertheless, film is the best starting point for appreciating both what these media have in common and what differentiates them. Specifically, they differ in respect of their representation of time: photography produces a still image of a moment frozen in time, whereas cinema employs film to produce a moving image that shows time passing. The representation of time, the technological control of time, and the viewer's experience of time are all features that have crucial importance for the application and the value of film media.

The term photography was established by John Herschel (1792–1871), in an 1839 presentation to the Royal Society in England. The Greek words photos (light) and graphis (paintbrush) or graphe (drawing) convey the idea of “drawing with light.” Light from a scene is recorded on a photosensitive surface, such as chemically treated film or an electronic sensor. In the case of photography, the data are subsequently processed and printed to produce a still image. A photographic image, or photograph, is sometimes called an exposure because the photosensitive surface is exposed to light for a finite duration of time and records only the data available during that exposure time. In the case of cinema, a large number of individual exposures are projected sequentially onto a screen and, from the perspective of the viewer, the result is a moving imageknown as a motion picture or movie. Cinematography is from kinesis (movement). The photographic image typically has just one relevant time constraint: the duration of the exposure time. The cinematic image has other relevant time constraints: in addition to the exposure time, the image is also a function of the speed of the cine-camerathe rate at which frames are exposedand the projection speedthe rate at which frames are screened.