The way to stop video pirates using camcorders to copy films in cinemas, Kodak claims, is to switch to a digital projection system that harnesses a new trick the company has dreamed up.
Unlike a film projector, a digital projector directs red, green and blue light onto the screen separately, using computer-controlled mirrors. In US patent 2004/0150794, Kodak proposes introducing a flicker of around 100 hertz into these beams, using a slightly different frequency for each colour. Though the flicker is too rapid to be detectable by the human eye, it interferes with the camcorder's electronics to make the red, green and blue content of the recording fluctuate unwatchably.
With today's film projectors, pirates can adjust their camcorder shutters to avoid flicker. But three colours flickering at slightly different rates in the new system makes this impossible.
To continue reading this article, subscribe to receive access to all of newscientist.com, including 20 years of archive content.