A Bright Future for Glasses-Free 3D Cinemas
New optics research by a team of South Korean scientists suggests it will soon be possible to watch a 3D film without the cumbersome 3D glasses.
Currently, 3D glasses feature polarised lenses which affect the way light enters our eyes. 3D cinema screens use two projectors displaying similar images which are slightly offset simultaneously on one screen. When wearing polarised glasses, each eye views only one of the offset images, creating an image with the illusion of depth which the brain interprets as 3-dimensional.
Optical engineers have since attempted to design 3D technology without the inconvenience of glasses. The parallax barrier method involves the creation of both a rear projection video and a physical barrier between the screen and the viewer. This concept can be compared to the slats in a venetian blind which limit the image each eye can see.
The South Korean team have designed a new way to experience 3D cinema, similar to the ‘venetian blind’ concept. In their design, polarisers are used to stop the passage of light after it has reflected off the screen. To do this, they apply a specialised coating to the surface of the screen, called a quarter-wave retarding film, which means light can no longer pass through the polarisers, thus creating the offset image effect. This offers a convincing 3-dimensional effect for the audience, without the need for glasses.
Glasses-free technology would be ideal for cinema-goers who are deterred by the uncomfortable frames offered by the cinema and would instead prefer the visual quality of a 3D film, with the viewing comfort of an ordinary 2D film.
But for now, hold on to your 3D frames because whilst this new research is promising, it may be several years before glasses-free 3D technology hits cinemas.