With 3D movies gaining in popularity and a number of 3D televisions coming onto the market in the near future it can be a bit confusing as to how each system works, there is currently no real universal 3D system with a number of methods fighting for overall control of the market, out of the 4 current methods to watch 3D there are 3 different 3D glasses that are used in conjunction with each type. These four types include polarizing, active shutter and lenticular technology, along with the age old anaglyph method we all know and love.
To understand how 3D glasses work you have to have a basic understanding of how depth perception is gauged by the human eye, quite simply each eye is spaced a distance apart which means the image each sees is slightly different from the other, the brain then does its thing and turns 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 looking at a 3D picture you are in fact looking at two slightly different images at once, the 3D glasses complete the process by blocking out one image from each eye so your two eyes are looking at two slightly different images each just like in real life, it really is quite simple but truly amazing!
The 3D glasses for each method are different, with anaglyph 3D you wear glasses that have red/blue lenses, what you are watching consists of two images per frame which is processed in each color so one image is filtered out by each eye. This is the old method that was used for the massive 3D movie boom of the 80's. The new more popular method used in cinemas is with the aid of polarization, with this method two images are shown each polarized differently, the 3D glasses you wear with this method are clear and each lens is polarized to allow only one of the two images into each eye, for example the right lens may be polarized to only allow horizontal light waves through while the left lens will only allow vertical.
There are two newer methods currently coming onto the market, used mainly for home use on new 3D televisions and monitors, these use active shutter and lenticular technology. With active shutter 3D you need special battery powered LCD glasses that block out alternate images displayed at high speed on a screen capable of a 120 Hz refresh rate. The other new method is lenticular technology which does not require 3D glasses at all because the TV itself creates the 3D image by reflecting light at slightly different angles towards the viewer with its unique screen.
So now you know the features of the three different types of 3D glasses you can just sit back and enjoy the show.
