The 3D Cinema Experience at Home
Going to the movies is one of my favorite things to do. I don't think I'll ever get sick of it. Since 3D movies have become all the rage I enjoy it even more now. You don't have to twist my arm to get me to experience the joys of a well made 3D experience. Fortunately I have four little girls who also like an outing to the movie theater and enjoy a good 3D film as much as the next person and not just movies made for girls either.
All 3D technology uses a system of presenting two slightly different pictures to the viewer but making sure your eyes see only one image each.
Because our eyes are separated slightly they each see the world from a different perspective. 3D movies mimic this effect thus giving the illusion of depth on a 2D screen. All 3D images are created this way but there are two or three different methods used to achieve the effect.
Anaglyph Stereo
Firstly, let's get the anaglyph method out of the way. If you've never heard the term before I am referring to the red and blue glasses that are usually manufactured from cheap cardboard with low grade plastic lenses. Each separate image is made up of either a red or blue tint. The red or blue lenses filter out the corresponding image so each eye sees the different perspective. This technique is a novelty at best and is not really suitable for enjoying 3D movies in high definition full color.
Active Shutter Glasses Stereoscopy
The technical term for active shutter glasses is alternate-frame sequencing. Each image is shown alternately on the screen. When an eye is not supposed to see the image it is blocked by the shutter over that eye going dark. When the technology was fairly new many people complained of a visible flickering in the image. It's for this reason that a TV needs to be have a refresh frequency of 120Hz or higher to double the frame rate of the animation on screen. Modern TVs and projectors are more than capable of this however.
Using active shutter glasses can have its downsides. The major disadvantage is that the glasses require power either through a cord or from batteries. This becomes very inconvenient when you have a large family. As they have been around for a while now prices for active shutter glasses and the TVs that use them have greatly reduced in price. Great news if you have a small or no family and only need one or two pairs of glasses.
Polarized Light Stereoscopy
Technology is always changing and new ways of displaying 3D imagery in the home are gaining market share. Polarized light stereoscopy, currently popular in cinemas, is now being made available in the home marketplace through the use of projectors. It's a very efficient way of creating 3D images as both images can now be displayed on the screen at the same time. Polarized lenses in the glasses filter out the corresponding pictures so each eye sees only one slightly altered image while blocking the other.
While it has some very good advantages the one major disadvantage it has at the moment is the cost. As it's still relatively new technology equipment is rather expensive. Another disadvantage is that you will need to buy a silver screen to get the best viewing experience. Silver screens reflect the light in such a manner as to ensure there is minimal depolarization for a crisper picture.
Because of it's advantages polarized light stereoscopy will eventually become the dominant method of playing 3D movies in the home. The glasses don't require batteries, are cheaper and also lighter than active shutter glasses. Your audience can be larger and more spread out due to the large viewing angles that polarized stereoscopy provides. The average pair of shutter glasses will darken the image by about 20%. Polarized lenses give you a much brighter image by only blocking out about 10%.
The author is a gadget addict and enjoys writing about his passion. If you're after more information on setting up your own home entertainment system check out his site at Best HDTV 2013
