Have any of you have watched a 3D (3 dimensional ) movie or played 3D games on the computer ? Ever wondered how you get such an effect, of objects flying out of the screen, or someone walking towards you. The effect seems so real that you actually duck or move a step back!!!
How do we get this 3 D effect? Our two eyes, view things at different angles. The brain then correlates the two images, created by each eye, to be able to perceive distance and depth of all that is happening around us, in other words, giving us a 3 dimensional (3D) vision, otherwise called binocular vision or stereovision. For example, look around you. What all do you see? Which object is closer to you and which is farther away ? You can automatically tell, which objects are nearer and which are at a distance. Try this with one eye closed. Even though you can still perceive distance, your accuracy decreases.
When you go to watch a 3D movie, you are asked to wear special glasses. These glasses perform the same function that your eyes do. The 3-D glasses feed different images into your eyes .The screen actually displays two images, one in red and the other in blue (or green) and the glasses cause one of the images to enter one eye and the other to enter the other and your brain does the rest.
Alternatively, two synchronized projectors project two different views onto the screen, the glasses allow only one of the images into each eye and the brain correlates the two sets of images, to create the 3 D effect! It is this effect that gives the sense of depth making objects appear to be coming "out of" the monitor.
You could even try taking a 3D picture with your own camera. What you do, is take two pictures of the same object by shifting the camera horizontally about 2½" (65mm) . A smaller shift is used for close-ups and a larger shift can be used for distant subjects. Alternatively, use two cameras and take one photograph with each simultaneously. Remember, this will work only if the object you are taking a picture of, is stationary. After you get them developed, place them together, and you will see a 3 D effect!!