subject: Exploring the Three Main Methods of 3D Imagery [print this page] Exploring the Three Main Methods of 3D Imagery
The popular method of creating a 3D image on a TV these days is to rapidly show two slightly different images one after the other. Each eye gets to see the correct image by way of glasses that rapidly block and unblock the image so each eye only gets to see one image at a time. As each eye sees the world from a slightly different perspective this effectively fools the brain into thinking that it is seeing an image with some depth.
The problem with the active shutter glasses is that they are expensive. People also have different shaped faces and like to buy glasses that suit. When you buy these glasses you are kind of stuck with the one style. If they happen to not fit correctly then you have to deal with expensive and uncomfortable glasses. You will also need a TV capable of the high refresh rates that 3D requires. If you have a TV that is more than 4 or 5 years it is most likely not 3D capable. Many TV brands have their own specific models of shutter glasses so your next step is to invest in these. They're expensive and if your whole family is watching the same movie then there is quite a few dollars worth of equipment sitting on your faces.
Luckily technology never stays still and we are already seeing new TVs available which can possibly eliminate the extra expense of glasses. New technology always costs more but TVs are becoming available that use polarized light to display the images. This is the same technique used in the movie theaters but on a smaller scale. The two pictures are projected onto the screen with polarized light. Each lens on the polarized glasses will only let one image through while blocking the other. As a result each eye sees a separate and slightly different picture than the other. Again, the brain is fooled into seeing a 3D image but the refresh and scan rate argument is effectively made mute as both images are displayed on screen at the same time.
For mostly solo viewing you can purchase LCD screens for 3D viewing without glasses. The methods these LCD screens use are largely a closely guarded secret but they essentially work by projecting the two slightly different images in different directions so each eye only gets to see one of them. This technique so far cannot be done for a widely dispersed audience or a large one. The reason for this is that there is a sweet spot which the viewer has to be in in order to get the two images correctly aligned. Any viewer outside of the sweet spot will only a see a 2D image at best or a blurry mess at worst.
