Production Design
Hitchcock-ian
Hitchcock is so Hitchcock that there's nothing to call him but… Hitchcock-ian.
Hitchcock films are practically their own genre. The director worked within the old Hollywood studio system, but was famous for creating dramatic, expressive, idiosyncratic scenes and effects. Psycho was shot on a much smaller budget than Hitchock's previous films (see Production Studio) but that only pushed the director to new heights of ingenuity.
The Opening Peep
The first height of ingenuity is a literal height. The film opens with a dramatic shot high above Phoenix. The camera pans across the city, and then swoops down to a mostly closed window shade. You then see inside, where Marion Crane, in her underwear, is canoodling with her boyfriend, Sam.
The move from way overhead to the private intimacy of the hotel room gives the viewer a sense of seeing everything—including things which aren't meant to be seen. Right from the opening shot, you're collaborating in uncovering sexual secrets. Marion (or Janet Leigh) is exposed—just like Norman will be, in more disturbing ways.
The Shower Scene
The single most famous scene in Psycho is also the most famous scene in all of Hitchcock's film… and also one of the best known in all of film history.
That would be the shower scene, with the water, the blood, and the shrieking, not-wearing-any-clothes Janet Leigh. The scene was so shocking, and so graphic, that it led Hitchcock to shoot the whole film in black and white. He thought that if the blood were really red, the film would be too much for the audience. Hitchcock; he's tasteful. (Gus Van Sant's 1998 shot by shot remake of Psycho finally presented the scene in color.)
The shower scene doesn't have any obvious special effects—there aren't any laser blasts or alien critters, a la Star Wars.
In fact, though, the scene was very complicated and difficult to shoot. It required 78 shot set-ups, and took seven whole days to film. In order to allow for the wide-range of views and camera angles required, the shower stall was built with removable walls, so the camera could view the action from any angle. For the shots in which the water streams around the camera, Hitchcock had an oversized showerhead constructed. He then placed the camera very close, so the water flowed all around it.
One of the trickiest parts of the shoot was the nudity. Nudity was not common in films in 1960. Leigh wore moleskin coverings over her breasts and crotch, but she was still, as she said in a later interview "pretty much "on display," so to speak." Security was a serious concern, to prevent strangers, or photographers, from seeing, or snapping pictures which could have been compromising and embarrassing. (Source)
A body double, Mari Renfro, was used for parts of the scene. For many years Leigh denied that Renfro was ever naked in the shower, but she eventually admitted that the other actress was nude in some instances.
Leigh herself was nude for a moment or two; her covering slipped during a shoot, and was not readjusted until the shot was finished. "What to do?" she asked. "… spoil the so-far successful shot and be modest? Or get it over with and be immodest? I opted for immodesty." (Source)
Down the Stairs
The other murder scene was also tricky. (Murders are hard to act out, as it turns out. You'd think you could just pick up a knife, and slash. But no. There's more to it.)
For the scene where Arbogast meets his fate, Hitchcock placed a camera in a cage hanging from the ceiling to shoot downward from above. In the murder sequence, where Arbogast falls backwards down the stairs, the actor Martin Balsam is actually sitting still and waving his arms. He's positioned in front of a screen showing a sequence (filmed earlier) from a dolly moving down the stairs.
The result isn't realistic, exactly, but it does give you an impression of vertigo and motion. It comes across as a kind of dream image—arguably creepier than if it were more believable. (The last wet sound of Arbogast being knifed is even creepier.)