In Mark Lewis' "home movies," Prof. A.N. Lewis is played by director Michael Powell, young Mark Lewis is played by Powell's real-life son, Columba Powell, and Mark's mother, seen lying lifelessly in bed, is played by Columba's real-life mother, Frankie Reidy.
This is the British counterpart of Psycho. Though it was banned for many years and so it did not become a box office smash like Psycho, filmmakers that saw it when it opened cite it as being similarly influential, maybe more so, because although the set pieces are more artfully constructed in Psycho, the killer in Peeping Tom is much more tragic and sympathetic, a major innovation for film at the time.
In his memoirs Michael Powell revealed his other candidates for the role of Vivian as being Joan Plowright (rejected as 'too sympathetic') and a young Julie Andrews (rejected as 'too famous'). He eventually chose Moira Shearer despite initially describing her as 'too glamorous'.
Mark uses a pair of unconventional, electric space heater like loudspeakers in his workshop. The Quad Electroacoustic model ESL-57 can be seen prominently in the background in the final scene with Mark playing the screaming audio tapes to Helen. The panel speaker design was ahead of its time. Unlike traditional "box" speakers with woofers, the ESL-57 uses ultra thin electrostatic panels to reproduce sound. The sonic advantages are unrivaled transparency and naturalness. "Sound and Vision" magazine hails the ESL-57 as one of the most important loudspeakers of the 20th century. The British speakers are now audio classics and highly prized in the audiophile community.
Vivian's small reel-to-reel tape recorder is a Grundig "Cub". First introduced in 1959 and advertised as a "miniature portable" tape recorder, it was battery operated, weighed about five pounds, and could record for approximately 30 minutes. MSRP was £27 ($76 at the time, or $636 in 2017).
The trivia item below may give away important plot points.
The film was heavily cut by the BBFC before release and consequently many scenes still have a ragged feel to them. The murders of Vivian and Dora were toned down, shots of nudity were deleted (including photos of nude girls in the album), the suicide of the killer was shortened, and scenes featuring the spike were also edited. Some dialogue was also cut (which explains the abrupt ending to the conversation between the policemen in the car). Although some cuts were restored in later video and DVD releases much of the edited footage is now considered lost forever.