 CONT: As was common practice on British television at the time,  exterior scenes were shot on film, while interiors were shot on  video in the studio. This lead not only to a discontinuity of  appearance between outdoor and indoor scenes, but many other  continuity errors as well.  An example occurs in the episode "A Private Place" (ep 2.5). Jean  Darblay is seen to approach the front door of a house. From the  outside (film), the door has a house number at the top, a letter box  and knocker at head height and a handle below the Yale lock. From  the inside (video), the door has no number or handle, and a  letterbox at waist height!