10 More Bizarre Ways Directors Tricked Audiences

Though it's generally accepted that Alfred Hitchcock shot Psycho on black-and-white film primarily for budgetary reasons, it's also been suggested that his decision may have been influenced by the film's content - namely that the iconic shower scene might've been "too much" for audiences in colour.

All the same, the monochromatic film stock required Hitchcock and his crew to think differently about how scenes were staged and shot, most of all the shower scene in which Marion Crane (Janet Leigh) is shockingly offed.

Traditionally, the Hollywood recipe for blood consists of corn syrup and red food colouring - it's a tried-and-true formula for realistic-looking blood that also looks great on camera.

But that recipe didn't look quite so good on black-and-white film, and so to produce blood which popped and contrasted with the sheer white of the porcelain bathtub, Hitchcock opted for Hershey's chocolate syrup instead.

With its darkness of colour and viscosity, it was a perfect substitute, and audiences largely remain none-the-wiser.