Viewing digital images in 3D, whether it be in a theater or with something like a VR headset, operate on the same principles of separating what the left eye sees from what the right eye sees. Coincidentally, both those cases also have something in common: the need to use some eyepiece or, worse, headgear, to experience “true” 3D visuals. Glasses-free 3D has been a holy grail, especially in the entertainment industry, where solutions like that found on the Nintendo 3DS are too expensive to put on a giant screen. Luckily, researchers from MIT are working on such a solution and are calling it, what else, “Cinema 3D”.
At its core, Cinema 3D works the same way as the Nintendo 3DS and some glasses-free 3D TVs, utilizing a technique known as parallax barrier. This puts slits in front of the image source, usually an LCD, that splits light and images so that one eye only sees one specific set of pixels or images while the other eye receivers a different set. This creates a parallax effect which ultimately replicates seeing in 3D.
The problem with parallax barriers is that they don’t scale well to larger screens, particular the sizes seen in cinemas. Cinemas are particularly problematic because each viewer is seated at a different angle from the screen, making parallax barriers rather ineffective. Ironically, it is also that very layout of the cinema that has given researchers at MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) the idea for a solution. In essence, because viewers are ultimately confined to their seats, they have very limited head movement range. So, unlike on a 3D TV or Nintendo 3DS, a screen can have multiple parallax barriers showing only a narrow range of images, so that each viewer basically gets his or her own barrier for their specific viewing angle.
That seems to work well on paper, but Cinema 3D is far from fulfilling the glasses-free 3D dream just yet. The prototype at the moment is no larger than a pad of paper but already makes use of 50 sets of mirrors and lenses. The researchers, however, are confident that a larger version will be just a feasible and affordable.