A Beginner’s Guide to … 3D entertainment
Don't know your passive display from your active glasses, then read on for everything you need to know about 3D.
The cinema and home-entertainment industries want to transport us to another dimension, but is it a journey worth taking? We investigate whether 3D is here to stay or just making another of its occasional comet-like passes.
If your idea of 3D is red and green glasses and the quick onset of headaches, it’s time to adjust your antenna. 3D technology has come on in leaps and bounds in recent years, the 3D effect is clearer and more convincing, the equipment is widespread in cinemas and becoming affordable for living rooms too. Meanwhile, film directors and other content creators are taking 3D more seriously than before, finding ways to use it as a storytelling tool rather than simply as a gimmick.
In this feature we’ll be looking at how 3D entertainment works, who’s producing it and what you’ll need to experience it in your home.
STEREO VISION
First, though, let’s talk about you. The chances are you have two eyes, which point in the same direction. Not everyone’s eyes do – one in fifty people have a condition called amblyopia, also known as a lazy eye. For them, the 3D revolution sadly isn’t going to have much impact.
The massive financial success of Avatar will ensure we see a lot more over the coming years, presuming your eyes are up to it.
People with normal eyesight have something called stereoscopic vision. The 6cm gap between our eyes means that each one sees the world from a slightly different point of view. Rather than perceiving a confusing double vision, our brains process the differences between the two images to create a mental model of the 3D space. This is called stereopsis. Another closely-related phenomenon is based on convergence. Hold a finger a couple of inches from your nose and you have to go cross-eyed to be able to focus on it. Look at something far away and your eyes can relax and point dead ahead.
The brain intuitively uses stereopsis and convergence to judge distances with impressive accuracy. However, people who have one blind or lazy eye are still perfectly able to navigate the world around them. That’s because stereopsis and convergence are just two of many techniques humans use to perceive distances. Our innate understanding of perspective is just as important. We also know what size various things should be so if a house appears very small, or an ant is very big, this tells us how far away it must be.