Where a miniature appears in the foreground of a shot, this is often very close to the camera lens — for example when matte painted backgrounds are used. Since the exposure is set to the object being filmed so the actors appear well lit, the miniature must be over-lit in order to balance the exposure and eliminate any depth of field differences that would otherwise be visible. This foreground miniature usage is referred to as forced perspective. Another form of miniature effect uses stop motion animation.
Use of scale models in the creation of visual effects by the entertainment industry dates back to the earliest days of cinema. Models and miniatures are copies of people, animals, buildings, settings and objects. Miniatures or models are used to represent things that do not really exist, or that are too expensive or difficult to film in reality, such as explosions, floods or fires.
The resurgence of the science fiction genre in film in the late 1970s saw miniature fabrication rise to new heights in such films as Star Wars, Close Encounters of the Third Kind, Blade Runner, and Star Trek: The Motion Picture.
1993 saw the release of Jurassic Park, which for many marked the turning point in the use of computers to create illusions, for which models and miniatures would have previously been employed.
Independence Day, Titanic, the Lord of the Rings trilogy, Godzilla and Casino Royale each represent highly successful films that have utilized miniatures for a large component of their visual effects work.
In spite of the pioneering work of Willis O'Brien and others in making stop-motion animated dinosaurs since the early days of cinema, producers have used optically enlarged lizards (often with horns and fins glued on) to represent dinosaurs to cut costs as, it was felt, the public saw dinosaurs as being simply giant lizards. The 'slurpasaur' appeared in the 1929 film version of The Mysterious Island. The first major use of the 'slurpasaur' was in One Million B.C. (1940) and, indeed, the special effects in this film were re-used often (in, for example, the 1955 movie King Dinosaur).
Other notable films with 'slurpasaurs' include Journey to the Center of the Earth and The Lost World (1960). The latter is notable for a 'dinosaur battle' wherein a monitor lizard and a young crocodile fight each other for real. The former is a rare example of lizards actually being convincing in their role — they are supposed to be Dimetrodons and actually look superficially similar to those creatures.
The public eventually became too sophisticated to accept 'slurpasaurs' as convincing dinosaurs, a factor which (together with the obvious animal cruelty aspect) led to their disappearance from special effects techniques.