3D Movies not so simple

Have you ever wondered how 3D movies work?  Well, I have been curious especially since I learned that the first 3D movie was "The Power of Love" which started playing on September 27, 1922. Yes, that does say 1922.  Now, obviously 3D movies have changed a lot since then, making them better for the tech savvy generation of today. 

Back in the 1920s, a simple technique was used to make the 3D movies.  The movies were made it two different colors and those corresponded to the two different colors of the 3D glasses tricking the eyes into thinking that the objects were popping out of the screen.

Today the 3D experience is a little different using a new technology of polarization.  There are two different methods of this polarization, linear and circular.  Both of these techniques are somewhat similar and they work by only allowing certain types of light through filters.  I am going to try and explain this is a way that makes sense to me.  When the film is made they use a camera that take two different images that are separated by the distance equal to the distance between an average eye.  This is so each eye can have a different filter in front of it(ie the lenses).  Each lense will allow for certain light waves to come through while the rest are reflected away.  In linear polarization one lense will be vertical and the other horizontal.  This allows for different lights to get through to each eye. 

Another way to look at it is thinking of it as the kids toy which only allows the blocks to go through each hole(see below).  Certain blocks or light can only go through each whole or lense.  Through this technique of polarization the 3D experience is made.