First Introduced: 1960
The Concept: William Castle, back at it again! For his 1960 horror-thriller 13 Ghosts (which, like House on Haunted Hill, became a cult classic that spawned a fairly recent remake, the P.T. Barnum of Hollywood introduced moviegoers to his latest innovation: a film process that allowed the audience to watch the movie with or without the baker’s dozen of disembodied spirits.
How It Worked: Kinda low-tech, kinda effective. Non-ghost scenes were shot and processed in normal black-and-white, over which the ghosts, presented as light-blue forms, were superimposed. Audiences were given their choice of cheap glasses with red filters, which allowed them to “see” the ectoplasmic forms; or blue filters, that hid the spirits from those with more delicate sensibilities.
Was It Successful? In William Castle’s mind? Probably.
Other Movies That Used This Technology: N/A