Article - Issue 49, December 2011
HOW DOES THAT WORK? - 3D Vision
Although 3D viewers have been available since Victorian times, their range and availability have increased rapidly in recent years. Two stereoscopic images viewed through lenses or filters exploit our own binocular vision to create the impression of a 3D world. New versions of this technology differ only in the methods of presenting separate images to each eye.
A 3D cinema audience view the action through ‘passive’ glasses fitted with opposite-circular-polarized lenses to create the desired effect. ‘Active’ systems use glasses that rapidly switch the screen images through electronically-controlled shutters to each eye in turn to achieve a 3D effect.
The development of the laser enabled the creation of the first practical optical holograms that produce 3D representations of an object, which are accurate when seen from different viewpoints. Holograms don’t require glasses and enable a person to ‘look round’ objects as though they were real.
Holograms though, contain far more information than two dimensional pictures and so making holographic movies remains a challenge because of the sheer quantity of data that needs to be processed and displayed. Super high resolution cameras that work with lasers have been developed from which simple video holograms of a moving object can be generated, but it will be many years yet before we will achieve the simulated reality of the Star Trek holodeck!