Depth of field

The depth of field, how much of scene in shot is in acceptable focus, is a crucial element in shot composition and controlling how the viewer responds to the image. Cinemagraphic fashion has alternated between deep focus shots (Greg Toland’s work on Citizen Kane (1941)), to the use of long focal lenses with a very limited depth of field only allowing the principal subject in the frame to be sharp. The choice of focal length and f-number control depth of field.