A scene from William Wyler's film, The Best Years of Our Lives, exemplifies deep focus. Note the in-focus figure in the phone booth in the background--best seen in the enlarged view of the image.

Deep focus is a photographic and cinematographic technique incorporating a large depth-of-field. Depth-of-field is the front-to-back range of focus in an image--that is, how much of it appears sharp and clear. Consequently, in deep focus the foreground, middle-ground and background are all in focus. William Wyler (July 1, 1902 - July 27, 1981) was a prolific and award-winning motion picture director. ... The Best Years of Our Lives is a 1946 movie about three servicemen (an airman, a soldier, and a sailor) trying to piece their lives back together after coming back home from WWII. It is based on a novel by MacKinlay Kantor, Glory for Me. ...

The opposite of deep focus is shallow focus, in which only one plane of the image is in focus.

A scene from Jean Renoir's film, Rules of the Game, exemplifies shallow focus. Note the out-of-focus figure in the background--best seen in the enlarged view of the image.

In the cinema, Orson Welles and his cinematographer Gregg Toland were the two individuals most responsible for popularizing deep focus. Their film, Citizen Kane (1941), is a textbook of possible uses of the technique. Jean Renoir Jean Renoir (September 15, 1894 – February 12, 1979), born in the Montmartre Quarter of Paris, France was a film director. ... Rules of the Game was the seven track demo cassette recorded by New Jersey third-wave ska band Catch 22. ... Orson Welles, photographed by Carl Van Vechten, 1937 George Orson Welles (May 6, 1915 – October 10, 1985) is generally considered one of Hollywoods greatest directors, as well as a fine actor, broadcaster and screenwriter. ... Gregg Toland (1904-1948) was an influential American cinematographer, most noted for his work on Orson Welles Citizen Kane. ... Citizen Kane is the first feature film directed by Orson Welles (he had directed two short films previously), and is loosely based on the lives of the newspaper magnate William Randolph Hearst, the reclusive aerospace and movie mogul Howard Hughes, and the Chicago utilities magnate Samuel Insull. ...

However, cinematic deep focus did not originate with Welles or end with him. Film-makers such as Erich von Stroheim and Jean Renoir experimented with the technique in the 1920s and 1930s. And director William Wyler also favored the technique in the late 1940s and 1950s--as can be seen in his post-World War II drama, The Best Years of Our Lives, from 1946. French film critic André Bazin championed deep focus as a major advance in the realism of the cinema and singled out The Best Years of Our Lives for analysis in his influential collection of essays, What Is Cinema?. Orson Welles, photographed by Carl Van Vechten, 1937 George Orson Welles (May 6, 1915 – October 10, 1985) is generally considered one of Hollywoods greatest directors, as well as a fine actor, broadcaster and screenwriter. ... Erich von Stroheim (September 22, 1885 - May 12, 1957) was a filmmaker and actor, noted for his arrogant Teutonic character parts. ... Jean Renoir Jean Renoir (September 15, 1894 – February 12, 1979), born in the Montmartre Quarter of Paris, France was a film director. ... William Wyler (July 1, 1902 - July 27, 1981) was a prolific and award-winning motion picture director. ... World War II was a truly global conflict with many facets: immense human suffering, fierce indoctrinations, and the use of new, extremely devastating weapons like the atom bomb. ... The Best Years of Our Lives is a 1946 movie about three servicemen (an airman, a soldier, and a sailor) trying to piece their lives back together after coming back home from WWII. It is based on a novel by MacKinlay Kantor, Glory for Me. ... André Bazin (April 18, 1918–November 11, 1958) was a famous and influential French film critic and film theorist. ... Realism is commonly defined as a concern for fact or reality and rejection of the impractical and visionary. ... The Best Years of Our Lives is a 1946 movie about three servicemen (an airman, a soldier, and a sailor) trying to piece their lives back together after coming back home from WWII. It is based on a novel by MacKinlay Kantor, Glory for Me. ...