The whole world seems to be talking about 3D this year, although half of them think 3D is dead before it starts, and the other half knows well that 3D is simply the next step in the evolution of digital video viewing. In real life, a lot of the technology described as amazing new 3D has been around for 20 years or more. Let's take a look at the three main types of 3D viewing there so you know what they're trying to sell you to at your local electronics store the next time you upgrade your TV.
First, what is 3D on Earth and why is it so important?
3D is how the average person sees the world around them – although you should know that being unable to perceive 3D is actually a common disability among many adults. Assuming that you see the world around you in 3D, how do you produce and reproduce something in a 3D way, like a movie or video game?
Being able to see in 3D means that your vision has a sense of depth, out of being. Your mind automatically calculates this for you by combining the images it gets from your left and right eyes, and addressing the small differences that occur when you look at something from a different angle. You can see what I mean by putting a finger in front of your eyes and looking forward. Close one eye, then open and close the other. Do it quickly and you'll see what each one looks like. Your finger is in a completely different place for each eye, but your mind regrouping the two and it appears that this means your finger is close to you.
Creating a 3D movie is as simple as using two video cameras, which are attached together at a distance approximately the same distance between the human eye. Each takes a slightly different recording, which when restarted into the human brain is able to show not only the visual scene but also the depth of everything you see. If the movie is animated on a PC, converting it to 3D becomes easy because it involves resubmitting all the movie data from a slightly different angle. If the movie was shot with 3D in mind from the start – as Avatar was – the effects are stunning.
3D games are actually incredibly easy to play, as all the data required to know where each object is in a 3D space is kept directly on the computer and can be processed in real time. In fact, many of us have been playing computer 3D games early 10 years ago, and technology is exactly like that found in a lot of 3D TVs and movie theaters today.
Assuming you have some 3D data, either a computer movie or animation or a video game – the problem is how to show it to the viewer. This is the technology aspect that we will discuss a little bit today.
Before I explain some of these, let me say that I'm not going to talk about trite red / blue glasses you get with 3D DVDs and cheap old comic novels, because that's not true 3D and the quality is amazing. Poor – regardless of the fact that all you see is red and blue then!
All of these 3D technologies basically boil down to how to get that slightly different picture of each separate eye – without the other eye seeing it either. Since regular TV displays the same image to both eyes no matter what you do, 3D presence is impossible for them. This is why you should never have a new TV if you are going to watch any kind of 3D material.
But how can we present a unique image to each eye?
1. Negative polarized glasses:
Polarization means making light rays point in only one direction. Usually, like comes in and pointed us in all different directions. The polarizing filter only allows light from one direction through. It is generally used in photography to avoid reflections – for example, if you try to take a picture of a window, you will not really be able to see the other side as the light reflects on it and in your lens. Using the polarizing filter, you cut that out, and you'll be able to see everything on the other side of the window.
The unique and useful properties of a polarized filter mean that by combining two filters we can make a kind of dimmer light. If you take two strips of polarizing film (think again about beginner classes in higher science now), and slowly rotate around it, at some point, you will allow most of the light to pass through and at another point they will leave the light equal. This is because in the first place the direction of light is aligned by the first filter, it is allowed to pass it by the next filter. However, when you rotate the second filter, you do it slowly so that the adjacent light cannot pass through and reach your eyes.
With respect to 3D technology, the ability to filter out specific light rays so that they cannot or cannot be seen from each eye means that we can present a unique image to each eye at the same time. How? We have two pictures on the TV side of things, and each picture can be drawn in a different direction. We then add the same filter to a pair of lightweight glasses, and each eye will only see polarized light in one particular direction.
Basically this is the cheapest way to do 3D, and it's far from perfect. It is used in large 3D cinemas where the quality of the movie is not as important as the experience, and may not be a full-length movie – like in Disney World, for example. The main benefits are that the eyeglasses are incredibly lightweight and inexpensive to produce, so it doesn't really matter whether people break them or go wrong. With them.
There are a number of inexpensive 3D TVs that are produced this year for the budget market, but I suggest you stay away from them. You tend to get a lot of mystery between photos (so you can see both left and right at once), and you really need to be in a dark room to get the best of this kind of 3D. Dolby also has a special system that appears to produce better quality than standard filters and is currently used in a number of better 3D cinemas.
2. Active shutter LCD glasses:
This is the best 3D quality you can get right now, and anyone who has contributed to knowing how good an avatar has been seen using this technique. Active LCD shutter means the renderer has to wear some very bulky glasses – each eye has a separate LCD screen inside, as well as an infrared signal receiver that connects it to the movie that is playing. Unlike the negative polarization that only shows both images on the screen at one time, active shutter modes display one frame at a time, alternating between views intended for the left and right eyes. The LCDs in the glasses turn them off and on, blocking the eye from the other. This turns it off and on very quickly so your mind simply merges the two images and forgets the other 50% part as each eye can't see anything.
The advantage of this method is that the quality is great with almost no "bleeding" for one image to the next. Unfortunately, some people claim that it gives them a headache. In all my years playing games with NVidia's active LCD shutter glasses, I've never had a headache, so I suspect the problem might just be something you get used to. When the TV first came out, I suspect there were similar complaints from a large percentage of the population.
This will be the consumer 3D platform of choice for many years to come. Yes, the glasses are noisy, but again we won't see everything in 3D. When I sit in front of the computer to play a 3D game, for example, I hardly notice it. The latest embodiment of NVidia's shutter glasses is actually lightweight, wireless, and recharges from a mini-USB socket. The mega models you get in advanced 3D cinemas are no longer huge because of the old technology, but just to make them more tear-resistant and discourage them from taking them home. If you are opposed to wearing glasses to display 3D content – well, you will wait long. Which leads us to the third way.
3. The scene displays:
3D viewfinder displays 3D content without the use of glasses. Although there are many competing technologies and there is a rapid development as we talk, the basic principle is that both images are displayed on the screen, and then a filter of the types arranges the images in different directions. When viewed from a certain angle, you will see the 3D effect. Most offer a variety of about 6 different angles that you can see, but outside you will lose the 3D effect and see just the blur of two pictures.
It's a relatively new technology, and it premiered last year in the form of the phrase "consumer's first 3D camera" by Fujifilm, which I had the opportunity to play with. The camera took 3D pictures, and was able to preview and play these images simultaneously on the small screen that does not have 3D glasses on its back. This year, Nintendo 3DS will be using a similar but somewhat improved version of the same technology to bring portable 3D games to the masses.
My experience with Parallax screens has been less than great. First, keeping your head in a steady position is annoying. Especially if you are seeing something in 3D, your head has a natural inclination to move around and wants to see it creating different angles. Also, the depth you can perceive on one of these screen is very poor. It doesn't really spit at you, even if it looks just like 3D. However, I couldn't see 3DS, so I wouldn't comment on it until it comes out. Either way, this type of 3D will not come to massive 3D TVs anytime soon, or perhaps at all.
I hope it gives you insight into all this young new technology. Don't forget to review my other tutorials.