3D Movies: How They Work

         

           I remember the first 3D movie I saw: The Deep Blue, a captivating compilation of creatures who call the ocean their home. I was a whale fanatic at the time, so you can imagine how much adrenaline was pumping through me while we were standing in line. While the actual film was fantastically done, the 3D illusion gave me a headache. To be frank, I could not tell the difference between a 3D movie, and a regular one. I have, since The Deep Blue experience, seen several other 3D movies. My hope was that my memory of The Deep Blue 3D movie was skewed (as it was years ago). I was sorely disappointed. In my humble opinion, I propose that the movie industry should not continue to invest so much money into the so-called 3D experience. The idea behind it, I must admit, is quite brilliant, but not well executed.

            The idea springs from studying the mechanisms of the eye. Humans (that have the ability to see with both eyes) use a process called Binocular Depth Cues. These give our brain information from the world, and turn it into a 3D scene. How this happens, is through binocular disparity. The left and the right eye are set, on average, three inches apart. This creates two unique views of your visual field. To test this out, you can hold one thumb in front of you, and the other thumb directly behind it. Now, if you were to close one eye and focus on the thumb in front, the thumb in the background will shift. With both eyes open you get a blurred “ghost” image of that thumb.

            In order to create a 3D image on a 2D screen, they use the same process.  If you take the red and blue 3D glasses off during the movie, you will notice the image is slightly blurred, and the colors seem a bit off. The image you are actually seeing is two separate images that are synced together on the screen. One side of the glasses will filter out the red wavelengths and let the blue wavelengths through, while the other filters out the blue and allows the red through. Despite only seeing one image with the glasses on, it is actually the two images overlapped, exactly like looking at a 3D object. Ultimately, your visual system is tricked into thinking the movie is 3D.

            As previously stated, the idea behind creating this 3D experience for movies is absolutely brilliant. Unfortunately, the product was not as gratifying. That, of course, is my opinion. I will leave it up to you to make your own judgment, after all, everyone's visual system functions differently. 

**This information is not a scholarly article, it is simply material I have learned studying Psychology at the University of Utah.**