With 3D movies gaining popularity and a number of 3D TVs coming onto the market in the near future, it can be a bit confusing how each system works, there is currently no true universal 3D system with a number of methods fighting for overall market control, out of the current 4 methods of viewing 3D, there are 3 different 3D glasses used in conjunction with each type. These four types include polarization, active shutter, and lenticular technology, along with the ancient anaglyph method we all know and love.
To understand how 3D glasses work you need to have a basic understanding of how the human eye measures depth perception, simply each eye is separated by a distance, which means that the image each sees is slightly different from the other, the brain then does its thing and converts these two images into a single image with the addition of depth. This process is used to create 3D images. When watching a 3D movie or 3D image, you are actually looking at two slightly different images at the same time. The 3D glasses complete the process by blocking out an image from each eye so that your two eyes see two slightly different images, each just like in real life. It really is quite simple but really amazing!
The 3D glasses for each method are different, with anaglyph 3D you use glasses that have red/blue lenses, what you are seeing consists of two images per frame that is processed in each color so that each eye filters one image. This is the old method that was used for the massive 3D movie boom of the 1980s. The most popular new method used in theaters is with the help of polarization, with this method you are shown two images each polarized differently, the 3D glasses you wear with this method are transparent and each lens is polarized to allow only one of the two images to enter each eye, for example the right lens can be polarized to only allow horizontal light waves while the left lens will only allow the vertical.
Currently, there are two newer methods coming onto the market, which are mainly used for home use in newer 3D TVs and monitors, which use active shutter and lenticular technology. With active shutter 3D, you need special battery-powered LCD glasses that block alternate images displayed at high speed on a screen with a 120Hz refresh rate. The other new method is lenticular technology which doesn’t require 3D glasses because the TV itself creates the 3D image by reflecting light at slightly different angles towards the viewer with its unique screen.
Now that you know the features of the three different types of 3D glasses, you can sit back and enjoy the show.