Hitchcock makes it very clear to us. There's an objective and a subjective camera, like there's a third- and a first-person narrator in literature.
Manuel PuigIf a spectator with a philosophical mind, somebody accustomed to reading books, gets the same kind of information in a movie, he might not fully understand it.
Manuel PuigI had stories that needed more space than the hour and a half or two hours a movie gives you.
Manuel Puig