January SITNFlash, Second Edition: 3D cinema: there’s a reason for wearing those goofy glasses

This article was contributed by Billy Lau

Do you remember wearing the red and cyan 3D eyeglasses when you were a kid? Well, 3D tech certainly has improved by leaps and bounds, and is turning into the latest fad in the entertainment industry. 3D films have matured from campy to epic, with the most recent blockbuster being James Cameron’s Avatar. The technology that makes 3D possible, known as stereoscopy, was pioneered at the turn of the 20^th century and popularized by the entertainment industry during the 1950s and onward. The biological basis of this three dimensional effect is called stereopsis (or depth perception, but we want to sound scientific), and relies on displaying slightly different images to each eye. Then, visual processing in your brain generates the sensation of depth. Stereopsis occurs naturally in everyday life, as your eyes receive a slightly different perspective of a single three-dimensional object because your eyes are in slightly different locations.

The main hurdle to perceiving depth from flat media (such as photographs or film) is that both eyes receive the same image. Because your eyes are getting the same information, the visual processing inside your brain interprets the scene as being flat. Over the past century, many techniques have been developed to overcome this problem and to generate a sense of depth in flat images. Here, we will briefly describe the science and engineering behind two of the most popular techniques and what new technologies are being developed.