In the picture above on the left is reproduced pictures depicting three pharmacy flask as if of the same size. Matter how carefully you saw these images, you will not find between the flasks is no difference in magnitude. Meanwhile, the difference there is, and rather significant. The bottles seem to be equal just because are not the same distance from the eyes or from photographic apparatus: a major Bank removed more than fine. But what of the three depicted cans closer, what next? It is impossible to define a simple viewing of the images.
The problem, however, is easily solved, if you seek the services of a stereoscope or by using the stereoscopic vision system, which is now discussed. Then you'll clearly see that out of the three bottles left far beyond the average, which in turn further right. The true ratio of the sizes of the bottles shown in the picture to the right.
Even more striking case are shown below. You can see the playback of photos, vases, candles and hours, both the vase and the two candles seem to be exactly the same size. In fact, between them is a huge difference in size: left vase almost twice the right and the left candle is much lower hours and the right candles. When stereoscopic viewing those pictures immediately found the cause of metamorphosis: the items are not arranged in one line, and placed at different distances: major - on, small - closer.
The advantage of stereoscopic “two-eyed” view before the “one-eyed” is here with great credibility.