Forced perspective is a technique that employs optical illusion to make an object appear farther away, closer, larger or smaller than it actually is. It manipulates human visual perception through the use of scaled objects and the correlation between them and the vantage point of the spectator or camera. It has uses in photography, filmmaking and architecture.
An example of forced perspective is a scene in an action/adventure movie in which dinosaurs are threatening the heroes. By placing a miniature model of a dinosaur close to the camera, the director may make the dinosaur look monstrously tall to the viewer, even though it is just closer to the camera.
Forced perspective had been a feature of German silent films and Citizen Kane revived the practice. Movies, especially B-movies in the 1950s and 1960s, were produced on limited budgets and often featured forced perspective shots.
Forced perspective can be made more believable when environmental conditions obscure the difference in perspective. For example, the final scene of the famous movie Casablanca takes place at an airport in the middle of a storm, although the entire scene was shot in a studio. This was accomplished by using a painted backdrop of an aircraft, which was "serviced" by dwarfs standing next to the backdrop. A downpour (created in the studio) draws much of the viewer's attention away from the backdrop and extras, making the simulated perspective less noticeable.