# Stereo Vision

In order to see in stereo properly, the left and right eyes see a slightly different view of an object, since they are in slightly different positions. In order to simulate this, images taken from different positions around the subject are selected to represent the subject to each eye. The number of images that are required to do this is based upon the distance from the subject to the user and the distance between the user's eyes, for which we use an accepted standard of 2.75 inches in the following calculations. As the user moves around the subject at a fixed distance his path forms a circle. The circumference of this circle is approximately equivalent to the number of images required for stereo (N) times the interocular distance of 2.75". If we set this equal to the standard equation for the circumference of a circle, where the radius is the distance between the user and the subject, we can calculate the number of images that are required to see stereo from a given distance.

Here are some examples of how many images would be required for stereo vision from various distances. These numbers reflect how many different views of the subject there would be from the given distances. However, as the distance increases our ability to perceive the difference between consecutive views diminishes.
```  5 feet requires  137 images
10 feet requires  274 images
15 feet requires  411 images
20 feet requires  548 images
25 feet requires  685 images
30 feet requires  823 images
35 feet requires  960 images
40 feet requires 1097 images
45 feet requires 1234 images
50 feet requires 1371 images
55 feet requires 1508 images
60 feet requires 1645 images
65 feet requires 1782 images
70 feet requires 1919 images
75 feet requires 2056 images
80 feet requires 2193 images
85 feet requires 2330 images
90 feet requires 2468 images
95 feet requires 2605 images
100 feet requires 2742 images
```

Back to VideoAvatar