The transfer to film meant that episodes would be shot using the single-camera setup, giving the production greater flexibility. The use of film production and the single-camera production style allowed more sophisticated visuals and camera angles, and more outdoor location shots, all of which greatly improved the look of the series. As was standard on British television filmed production through the 1960s, all location work on Series 4 was shot mute, with the soundtrack created in post-production. Dialogue scenes were filmed in the studio, leading to some jumps between location and studio footage.