In 1833, an English scientist Charles Wheatstone, discovered that because human eyes are not at exactly the same place, objects viewed through eyes are not the same, thus creating an illusion of depth. And five years later, according to what he discovered, he invented the stereoscope. Stereoscope is a binocular device through which a pair of monocular images was projected to both eyes in such a way that the optic axes converge at the same angle, which gave the impression of a solid 3D image. Since then, people started to have a concept of stereo view. However, Wheatstone's invention was impractical until Sir David Brewster, a Scottish physicist and experimenter of optics, discovered that a 3D effect could be observed in repeated patterns with small difference in 1844. Brewster used what he