3D TV

Don't worry, a shark won't actually come out at you even though it might seem like it!

Of course no television can actually broadcast in three dimensions. It is always going to be a two dimensional screen, so you don't have to worry about anything actually coming out and hitting you! The illusion is created by understanding how the eye work and how it creates depth. This does mean that for the 3D effect, you are going to need 3D glasses.

How Do 3D TVs Work?
Before getting onto how 3D TV glasses work, it is important to understand how a 3D television works. Now you might think that you don't need a 3D TV because you have already watched a film or television show in 3D using coloured glasses. If that is the case, then you probably noticed that the colour was strange, and you had to sit in one ideal spot for it to work properly. That's if it worked at all.

That is not how the most advanced forms of 3D work any more. Instead of broadcasting in slightly different colours for your coloured glasses to polarize differently for each eye, the work is done with more subtlety. For the mind to create depth properly, it needs input from both eyes, which have slightly different perspectives, to be able to judge where things really are. How a 3D TV makes use of this is, instead of broadcasting one image at around 25 frames per second, it alternates between images taken from slightly different perspectives at double the rate. This is just like your eyes capturing images from the world from slightly different perspectives, and allows for the 3D effect.

So Why Do We Need 3D TV Glasses?
Since 3D TVs broadcast two different perspectives, in a similar fashion to the way your eyes see the real world, why do we need 3D glasses at all?

Well, as you may have realised already, what you need is for your right eye to only see the image from the perspective slightly to the right. And your left eye only to see the image from the perspective slightly to the left. That is what 3D TV glasses achieve. The illusion of depth is thus created.

How 3D TV Glasses Work
The only question that remains to be answered in this (basic) explanation of how the 3D effect is produced is how 3D glasses work. Actually there are two main ways, not counting the old fashioned anaglyph, two-colours method.

Modern 3D glasses are a lot more refined than the two-colour glasses of old. The first is to use polarised 3D glasses. These work on the same principle as the coloured glasses, in that the image is polarised differently for each eye. The left lens only allows through the image meant for your left eye and the lens on the right only lets in the image meant for your right eye. If that sounds complicated and difficult to do, then you'd be right, and it is one of the reasons that normal TVs are not able to broadcast in 3D.Those types of glasses are also called passive 3D glasses

The other main type of 3D TV glasses are called active shutter 3D glasses. As the names suggests, instead of polarizing each image, it uses an LCD screen in the 3D glasses to physically black out one eye at a time at the exact same rate at which the images are alternating in the screen. In other words so fast that your mind can't keep up and won't notice it.

These are both excellent methods, and which one you use will depend on the make of 3D TV which you purchase. Once you do, all you have to do is put on your glasses, sit back, and hold on tight!