3D TV has always had one major drawback: glasses. While these glasses have the potential to be attractive, they are more likely to be unappealing and uncomfortable to the majority of people. For this very reason, 3D in the home theater has yet to get off the ground. Thus, we patiently await realization of the dream that we can watch 3D without glasses in the comfort of our own homes.
The technology exists, and has existed for over a century, to show 3D images without glasses. It's called autostereoscopy. That's right! Humanity solved that problem a long time ago. So what's keeping it out of our homes? Despite this tech's origins in relative antiquity, perfection is not an easy trait to attain. But thanks to companies such as Dolby and Stream TV Networks seeking create the best 3D TV technology, we're almost there.
So, how does it work? Autostereoscopy takes advantage of parallax. In this instance, parallax is the distance between your eyes, the reason we experience life in three dimensions. To watch 3D television, with or without glasses, requires two images, always. Each of these images is directed to a different eye using a variety of methods, including passive glasses, active glasses, parallax barriers and lenticular arrays. Let's talk about parallax barriers and lenticular arrays since these don't require glasses, and that's what you want, right?
Parallax barriers are miniscule lines between pixels on a screen. These physically block light so that each eye can only see its intended image. Despite their effectiveness, these often darken the image and make it difficult to see. For examples of parallax barriers in action, look no further than the Nintendo 3DS.
Lenticular or lens arrays are little more common, and you probably don't even realize it. Billions of stickers, trading cards and novelty items have wiggle images that are created using this technology. The vertical or horizontal plastic ridges on these ostentatious novelties are the lenticular arrays. The principle behind this rests in each lens, or ridge, as it bends light differently depending on how you hold the card. From here, the lenses can make an image move, transform or create 3D illusions.
These two techniques seem like they would be easy to incorporate into the modern 3D TV, it's just not that simple. The parallax barriers have to overcome dark image problems. Similarly, lenticular arrays need further development to make the imaging process more effective. Both processes could benefit from lower production costs and could become economically feasible in the future. Once this happens, 3D without glasses will finally make it to the majority.
Now you know the basics of 3D without glasses. So how long do you have to wait for this? This technology is unlikely to hit the market for at least another couple of years. Even then, it will only be available on the top tier models, so average consumers likely won't be able to afford it. It's possible that all TVs will have this feature in a decade. In the meantime, if you must have 3D in your home theater, you'll have to put on some glasses to watch a 3D HDTV or projector.