Film is a term that encompasses individual motion pictures, the field of film as an art form, and the motion picture industry. Films are produced by recording images from the world with cameras, or by creating images using animation techniques or special effects.
Films are cultural artifacts created by specific cultures, which reflect those cultures, and, in turn, affect them. Film is considered to be an important art form, a source of popular entertainment, and a powerful method for educating -or indoctrinating- citizens. The visual elements of cinema give motion pictures a universal power of communication; some movies have become popular worldwide attractions, by using dubbing or subtitles that translate the dialogue.
Traditional films are made up of a series of individual images called frames. When these images are shown rapidly in succession, a viewer has the illusion that motion is occurring. The viewer cannot see the flickering between frames due to an effect known as persistence of vision — whereby the eye retains a visual image for a fraction of a second after the source has been removed. Viewers perceive motion due to a psychological effect called beta movement.
The origin of the name "film" comes from the fact that photographic film (also called film stock) has historically been the primary medium for recording and displaying motion pictures. Many other terms exist for an individual motion picture, including picture, picture show, photo-play, flick, and most commonly, movie. Additional terms for the field in general include the big screen, the silver screen, the cinema, and the movies.
Mechanisms for producing artificially created, two-dimensional images in motion were demonstrated as early as the 1860s, with devices such as the zoetrope and the praxinoscope. These machines were outgrowths of simple optical devices (such as magic lanterns) and would display sequences of still pictures at sufficient speed for the images on the pictures to appear to be moving, a phenomenon called persistence of vision. Naturally, the images needed to be carefully designed to achieve the desired effect — and the underlying principle became the basis for the development of film animation. |