In 1943, Biroc began his career as a motion picture cameraman in the Army Signal Corps. Two years later, he filmed the brutalities at the Dachau concentration camp in Germany while serving as captain of the sixth detachment alongside George Stevens's Special Motion Picture Coverage Unit. The end of the war marked a significant period in Biroc's life as he achieved the rank of captain and eventually, the rank of major. He also obtained his first credit as cinematographer for "It's A Wonderful Life" (1946). Following this, Biroc “served as cinematographer for the first 3-D American feature length film in color” titled "Bwana Devil" (1952).