He appeared on stage in the early 1910s, and made his screen debut as an actor in Thomas H. Ince productions.
In the 1920s Dull held managerial posts with United Artists and Fox Film.
In 1929 and 1930, for United Artists, he supervised (and sometimes directed) classical-music shorts with orchestrations by Hugo Riesenfeld and live-action visuals conceived by William Cameron Menzies.
[2] He joined Metro-Goldwyn-Mayer in 1936, working as general superintendent, production assistant, unit manager, and (in 1938-39) associate producer.
He won an Oscar in 1948 for Best Documentary Feature: The Secret Land,[3] showing a naval expedition to Antarctica.