3D Television

Overview: When you place different filters in front of each eye, different direction polarizers for example, you can create a stereoscopic 3D effect. Stereoscopic means placing 2 identical images, that are slightly offset, on top of one another. When these images use different polarizing directions, and you use matching polarizers, one over each eye, your brain perceives this as a 3D image.

Supplies: 3D TV, 3D DVD Player, 3D DVD, Polarized 3D Glasses

Objectives: See how the most modern type of 3D movies works

Setup:

  • Plug in 3D tv cart
  • Turn on TV
  • Turn on DVD player

How to run the demo:

  • Start playing DVD, with or without sound
  • Pass out polarized 3D glasses and watch the magic happen

What’s Happening?

To create a 3D movie two images are projected overlayed onto the same screen through circular polarizing filters of opposite handedness. (See the What’s Happening section on the polarization page to learn about linear polarization.) Circular polarization works similar to linear polarization, except instead of the polarization running up and down, or left and right it works in left hand or right hand spirals.

The glasses you wear to view the movie contain a pair of analyzing filters (a quarter wave plate and a linear polarizer) of opposite handedness. Light that is left-circularly polarized is blocked by the right-handed analyzer, while right-circularly polarized light is blocked by the left-handed analyzer. When you view each of those through one eye your brain sees two different images and interprets that as a 3D image.

Using circularly polarized light to create movies is a huge advantage over linearly polarized light. Because of the properties of circular polarization you can sit anywhere in the theater as well as move and tilt your head and get the same viewing experience. With linear polarization your best viewing position is directly in the center of the screen. You also don’t want to move your head as twisting or tilting can cause the opposition of the polarizers to bleed into each other and distort the image.

The predecessor to polarized 3D movies is Anaglyph 3D

Learn more: (external links)