Psycho is regularly voted among the scariest movies ever made, and definitely the most frightening of Alfred Hitchcock's work - and that's with stiff competition.
How much do you know about the film that made the prospect of showering absolutely terrifying? Peruse this gallery, but BEWARE...no, you're fine. Just carry on.
(Images: All Star)
Alfred Hitchcock kept Janet Leigh on edge throughout filming by hiding the different versions of the 'Mother' dummy in her dressing room closet.
Hitchcock bought the rights to Robert Bloch's novel for $9,500. He is said to have asked his assistant to buy all the copies she could find so that as few people as possible would know the film's twist.
The novel from which the film was adapted is loosely based on the notorious murderer Ed Gein. Like Norman Bates, Gein had a domineering mother to whom he kept a shrine and dressed in women's clothes. Gein lived just 40 miles from Psycho author Robert Bloch.
Hitchcock insisted that there was no late admittance allowed at showings of the film, in order to preserve the twists. This caused lines around the block of people waiting to see the film, which proved to be excellent publicity.
The film makes some significant changes from the book. Screenwriter Joseph Stefano's masterstroke was making Marion Crane seem the central character, although she only features in two chapters from the book.
The three-minute shower scene features 77 different camera angles and 50 cuts. It took seven days to shoot.
There is a popular myth that Hitchcock did not direct Marion's death scene, but both Janet Leigh and assistant director Hilton Green have refuted this countless times.
Psycho earned over $15 million on its initial release, making it Hitchcock's biggest hit by some distance.
Paramount was so against the idea of Hitchcock making Psycho that it only agreed to distribute the film when Hitchcock offered to finance the production himself and forgo his $250,000 fee. Cannily, he took a 60% stake in the film's box office.
The Bates Motel used in the film is still standing at Universal Studios in Los Angeles.
Janet Leigh received $25,000 for her part in the film, just a quarter of her usual fee. She took the cut in order to work with Hitchcock. Anthony Perkins, despite being an established star, earned only a little more with $40,000.
For his signature cameo Hitchcock appears briefly outside Marion's office window wearing a stetson.
The shower scene was not originally intended to have any music, but composer Bernard Herrmann insisted that he be allowed to play Hitchcock his score. Hitchcock loved the now famous screeching effect and increased Herrmann's salary.
In the novel Marion Crane is beheaded in the shower rather than stabbed to death.
Psycho almost didn't happen. Hitchcock was planning a film called No Bail For The Judge with Audrey Hepburn, but that fell through so he proceeded with Psycho.
In the film's opening scene Marion is wearing a white bra because she is still innocent. Once she has stolen the money she's seen in a black bra to echo her dark turn.
Vera Miles wore a wig throughout filming as she'd shaved her head for her role in 5 Branded Women.
Psycho was the first American film to show a flushing toilet. Joseph Stefano wanted to include one for realism and wrote it into the scene where Marion disposes of the paper so that it couldn't be cut by censors.
The Bates house was largely based on an Edward Hopper painting called The House By The Railroad.
Bernard Herrmann's score is played entirely on stringed instruments.