A 3D stereo view is the viewing of objects through any stereo pattern.
History
In 1833, an English scientist Charles Wheatstone, discovered that because human eyes are not exactly the same distance apart, objects viewed through eyes are not the same, thus creating an illusion of depth. Five years later, according to what he discovered, he invented the stereoscope. The 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 gives the impression of a 3D image. Since then, people began to understand the 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 discovered in building the stereo camera. The stereo camera combined the refracting stereoscope with two separate cameras which were placed slightly apart. The monocular pictures through the cameras gave the resulting image a 3D effect.
In 1846, W Rollman invented 3D anaglyphs, which are two sets of superimposed identical line drawing(one in blue and the other in red), which when viewed through red and blue glasses, appeared to be three-dimensional. And then in 1891, Louis Ducas du Haron created the first printed anaglyphs-photographs consisting of two negatives(one in blue or green, the other in red) printed on the same sheet of paper to form a stereoscopic photograph.
In 1930s, inventor Edwin Land replaced the red and green filters in the du Haron's anaglyphs with two planes of polarised light.
In 1959, Dr. Bela Julesz, a psychologist researching on depth perception and pattern recognition, created random-dot stereo images, which are pictures consisting of a uniform, random distribution of dots.
Viewing techniques
If one has two eyes, fairly healthy eyesight, and no neurological conditions which prevent the perception of depth then one is capable of learning to see the images within autostereograms. "Like learning to ride a bicycle or to swim, some pick it up immediately, while others have a harder time."
Most stereo image are designed for divergent (wall-eyed) viewing. One way to help the brain concentrate on divergence instead of focusing is to hold the picture in front of the face, with the nose touching the picture. With intense lighting, the eye can constrict the pupil, yet allow enough light to reach the retina. The more the eye resembles a pinhole camera, the less it depends on focusing through the lens. In other words, the degree of decoupling between focusing and convergence needed to visualize an autostereogram is reduced. This places less strain on the brain. Therefore, it may be easier for first-time autostereogram viewers to "see" their first 3D images if they attempt this feat with bright lighting.
Another way is to stare at an object behind the picture in an attempt to establish proper divergence, while keeping part of the eyesight fixed on the picture to convince the brain to focus on the picture. A modified method has the viewer focus on their reflection on a reflective surface of the picture, which the brain perceives as being located twice as far away as the picture itself. This may help persuade the brain to adopt the required divergence while focusing on the nearby picture.
For crossed-eyed autostereograms, a different approach needs to be taken. The viewer may hold one finger between their eyes and move it slowly towards the picture, maintaining focus on the finger at all times, until they are correctly focused on the spot that will allow them to view the illusion.
Implementation
1.3D film. A 3D or 3-D (three-dimensional) film or S3D (stereoscopic 3D) film is a motion picture that enhances the illusion of depth perception. The most common approach to the production of 3D films is derived from stereoscopic photography. In it, a regular motion picture camera system is used to record the images as seen from two perspectives (or computer-generated imagery generates the two perspectives in post-production), and special projection hardware and/or eyewear are used to provide the illusion of depth when viewing the film. Some methods of producing 3D films do not require the use of two images. 3D films are not limited to feature film theatrical releases; television broadcasts and direct-to-video films have also incorporated similar methods, especially since the advent of 3D television and Blu-ray 3D.