 The light levels in the British Museum were insufficient to allow  Hitchcock to film the final chase scene in the museum. Without  informing the producer, Alfred Hitchcock (I) (qv) used the  Schufftan process (developed by German cinematographer  Eugen Schüfftan (qv)). This involved taking still photos of the  interior of the museum, then reflecting the photos in a mirror with  certain parts of the silvering of the mirror scraped away to allow  people (entering a door, for example) to be filmed through the  mirror so that they appeared to be present in the museum (in later  years, American development of traveling matte and other process  photography methods largely replaced the Shufftan process).