I have always been fascinated with 3D entertainment. For me, it introduces an almost indescribable sensation that traditional film does not offer. Although traditional film does offer the primary components in depth perception, the addition of stereopsis, or parallax, can greatly change a scene. Explaining stereopsis can help explain 3D technology fundamentals — the difference between the positions of our eyes on our head provides two slightly different images that our brains assimilate into one image. This difference supplies information that the brain uses to calculate depth in the scene. 3D technology simulates stereopsis before the image reaches our eyes. 3D films must be filmed in a way that footage is retained from two differing angles based on the average distance between human eyes. Animated films must be rendered using two virtual cameras.
Active shutter 3D systems utilize glasses that alternately block sight from each eye as the television alters between the slightly different images. The advantage here is in the retention of resolution for the viewer while watching the film but the glasses are heavier and more expensive.
Passive 3D systems use simple glasses that have lenses with differing polarization. The TV then uses a filter to polarize the odd and even lines of pixels differently to match the polarization of each eye. The glasses are cheap and light, but there is a loss of resolution for each eye. A viewer may notice black lines if sitting too close to the TV.
One last 3D method known as Autostereoscopy lets the viewer to watch 3D TV without the need of specialized glasses. The TV creates two images and reflects slightly different images to each eye. One issue this introduces is the limited viewing angle but the use of multiple lenses could provide multiple angles of viewing. There are limitations with this option but with the advancements of technology, it may eventually make its introduction to consumer electronics. One possible solution both the passive and autostereoscopy methods would benefit from in terms of resolution retention would be the use of 4K TVs.
Other advantages and disadvantages exist for both types of 3D TV systems and further research would help one decide which is best for the situation. While this technology is not yet perfect, it will most likely continue to improve and better simulate the natural eye functions. While there is some worry as to health risks, there doesn’t seem to be any evidence for or against the claims. Everyone is not and will not see the usefulness of 3D home entertainment, but the advancements are exciting for those of us that do.
Image source: Photodune