Writer Hans Janowitz claims to have gotten the idea for the film when he was at a carnival one day. He saw a strange man lurking in the shadows. The next day he heard that a girl was brutally murdered there. He went to the funeral and saw the same man lurking around. He had no proof that the strange man was the murderer, but he fleshed the whole idea out into his film.
Played at one Paris theater for seven years.
The sets were made out of paper, with the shadows painted on the walls.
The physical appearance of Caligari was inspired by portraits of the German philosopher Arthur Schopenhauer.
The final look and feel of the film was based as much on low-budget practicalities as it was on creative inspiration and expressionism. Electricity was strictly rationed in post-WWI Germany at the time the film was being shot, so director Robert Wiene ended up simply painting light beams on backdrops. Shooting on severely confined sets forced him to use unusual camera angles.