An iris shot is a technique frequently used in silent film in which a black circle is closed to a scene. 
The iris shot is divided into two types depending on their use. An Iris is used at the end of a scene, and an iris is used at the beginning of a scene, often after a previous iris out.
Some non-silent era slapstick comedy, such as that of Red Skelton , Benny Hill , and Warner Bros. ‘ Road Runner cartoons, employ the iris shot as an homage to the silent film era. Iris shots are used to put a particular aspect of film, usually something of importance.
In some cartoons and live-action films, iris shots are used as a way to break the fourth wall , usually for comedic purposes or to allow characters to interact with the audience. Examples of this issue of iris, the audience with a liner before the iris, or holding the iris open to try and continues to monologue.
- Jump up^ Konigsberg, Ira (1989). The Complete Film Dictionary . New York: The Penguin Group. pp. 174-5. ISBN 0-452-00980-4 .