What is 3D: The basics of mechanism and technology

Man has two eyes. While one eye is sufficient to see, two eyes are required for giving it a dimensionality or sense of depth. How does that work?

The human eye is around 4 cm apart (approx.) each eye views from a different angle and generates a unique image.

For an exercise hold a bottle in front of your eye. Look at it and then you will see the difference in the angle+image of your right eye and angle+image of your left eye.

Both these images reach your brain and they are merged to create a single image. The difference between the images gives your a brain an idea of the z axis - the depth.

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When you see an image from a single source like a painting or a TV, both your eyes see the same image. The trick is to make your each eye see a different image. Hence all the 3D image viewing requires mechanisms to ensure that your right eye sees slightly different than your left eye (basically extend real world to that image). And hence all 3D viewing requires the viewer to wear the crazy 3D goggles (there is an exception autostereoscopy but that restricts the head movement or number of people who can watch at the same time).

Now the goggles employed to separate the image viewed by the right and the left eye could be of various types depending on what method you are employing to mark the separation between the two images:
1) Anaglyphs - Red Cyan glasses
2) Polarizer - Polarized glasses
3) Alternate frame sequencing - with Alternate Shutter glasses(called head gear)
4) Texas DLP technology (copyrighted) that has mirrors corresponding to a chip corresponding to each pixel

We will discuss each of them as we move up.

But note- 3D is not just about mastering the technology. 3D is about framing right and knowing how to frame so that the 3D effect is maximized.
For example - converging lines don't work in 3D and lots of other crazy tips I would share as we go ahead.