The holy grail of display technology is to replicate what you see in the real world. This means video playback in 3D — but when it comes to displays, what is 3D anyway?

You don’t need me to tell you how far away we are from succeeding in replicating real life in a video display. Despite all the hype, there are only a couple of different approaches to faking those three-dimensions. Let’s take a look at what they are, and why they can call it 3D, but they’re not fooling us into believing we’re seeing real life… yet.

My Superpower: I See Things Different (But So Do Many Others)

When you share a secret with the world you lose all element of surprise, but this one’s too good to keep under wraps. I have a genuine bona-fide superpower, one that all those comic-book authors would have no doubt incorporated into their characters had they only thought of it.

It’s pretty mundane really, no radioactive flies or anything were involved, instead I have a thing called a strabismus. It’s a congenital condition, my left eye looks about 20 degrees to the left of centre, and the superpower it conveys is that I can see over my shoulder to something of what is happening behind me. I should have a cape or something, but sadly our Hackaday overlords’ budgets don’t stretch that far.

In reality having peripheral vision that stretches at its leftward extreme much further than everyone else’s isn’t much use beyond a party trick, but having a strabismus has another more significant effect. Since the two views on the world that my brain could see while it was developing in my very early childhood were not aligned with each other, I don’t have stereoscopic vision. A quick read around the subject reveals that I share this to some extent with as many of 12% of people, so perhaps quite a few readers will understand. That’s not to say that I and people like me inhabit a 2-dimensional world as if viewing it through a TV screen though. Instead we see in 3D in a different way to people with stereoscopic vision, and as a result the subject of 3D imaging has become something of a personal fascination.

Types of 3D Displays

Stereoscopic Displays | If you think of a 3D display, the chances are you will first imagine a stereoscopic one. Watching Avatar in a cinema with a set of polarised glasses perhaps, or even the vomit-inducing Nintendo Virtual Boy console. Your brain is being tricked into believing it has a 3D object in front of it through the means of each of your eyes being individually fed a view of the same scene but from slightly different viewpoints. It’s easy to make a stereoscopic imaging system for the relatively trifling expense of an extra camera and a bit of display trickery, and delivering the correct image to each eye is a long-ago-solved problem.