# 3D Glass. How stuff works

Have you seen a 3D Film? It is really interesting and the images appear as seen in normal eyes in a  Three dimensional view. Now 3D films, 3D TV etc are popular and we are on the verge of a 3D boom. Special kind of glasses are provided in movie theaters to watch 3D Films. The 3D imaging or 3D animation uses special technology to record the film and special kinds of glasses are necessary to view the film. If you remove these glasses and watch the same movie with naked eyes, the incredible 3D experience would vanish and you would land up viewing distorted/blurred pictures. The 3D effect is due to an illusion of the depth to the viewer. Let us see the trick behind the 3D technology.

Simply you can make a 3D illusion

To understand the working of 3D Glass, here is an example. Take a ball or lemon. Simply watch with both eyes, and then close one eye as you keep watching with the other eye. Now close this eye and open the previous eye. Repeat the process three or four times. You can see the ball is moving back and forth. This feeling is due to the depth created in visualizing the ball with different eyes.

The 3D Movie consists of two images super imposed. The 3D glass is designed to feed these images into the eyes. The 3D glass passes one image into one eye and the second one into the other eye. There are two common methods to achieve this. Some glasses use polarization method while some other uses Red/Green or Red/Blue 3D Method.

Polarization method

Polarization method uses special glasses to pass different images into the eyes. The system has two synchronized projection lenses to project two respective views of the image each having a different polarization. The glass is provided with two polarized filters arranged at 90 degree to each other. One filter passes the light with the same polarized plane while preventing the other. The other filter do the same thing in the opposite manner. So each eye sees a different image. As a result of this two images reach our eyes and create a sense of depth resulting in high quality 3D effect.

Polarized light

Red/Green or Red/Blue method

Here two colored glasses are used. The image also has dual colour. One image is projected into the screen in Red colour while the other image in Green / Blue colour. The 3D glass filters and allows Red image to pass into one eye and green image into the second eye. The brain is actually creating the 3D image.

Red / Green Image                                                                                                   Red/Blue Image

How to make a Home made 3D Glass
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