Orson Welles's Citizen Kane (1941) is a compendium of photographic techniques combined with a creative use of sound. Welles and cinematographer Gregg Toland developed or enhanced techniques for allowing the drama to develop on multiple planes of vision and sound. Deep focus photography, which Toland had used in more limited fashion in earlier films, allowed actors and objects to remain in focus whatever their distance from the camera. Using this method, multiple actions could be staged within a single frame and remain comprehensible, allowing for complex interactions between foreground and background.
The soundtrack followed suit. Welles created a complex soundtrack that merged multiple dialogues, sometimes spoken simultaneously, and music into a comprehensible whole. Toland also developed ways to light sets so that it was no longer necessary to avoid extreme low-angle shots for fear of exposing the lamps; the effect of allowing different, often extreme, camera angles was to intensify the meaning of a given shot or scene.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.