I love going to the movies. 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. I don’t need much excuse to go and experience the wonders of the fantastic new effects that 3D promises. Luckily for me I have four little girls who give me the perfect excuse to see all the latest kids animations with 3D effects.
3D movies work by making sure each eye sees a different image to the other, both taken from a slightly different perspective.
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. Whatever method of seeing 3D you are using they all use this same principle but go about it in slightly different ways.
Anaglyph Stereo
Once a popular method anaglyph is now more of a novelty due to its poor picture quality. In case you don’t know the term anaglyph refers to the red and blue glasses which are usually made out of cardboard. The two separate images for the eye are created with either a red or a 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
Active shutter glasses use a method that is technically known as alternate-frame sequencing. Each eye has its view blocked by the lens going dark when the image that it is not supposed to be seeing is on the screen. For this method you effectively need to double the frame rate of playback as each eye is only seeing half of the animation. These higher frequencies are becoming the default standard of new model TVs and projectors.
Using active shutter glasses can have its downsides. The major disadvantage is that the glasses require power either through a cord or from batteries. When you have a large family that can add up to quite a mess of cables or quite a lot of batteries. 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
Technological research has created new ways of displaying 3D imagery in the home. A method that is currently being used in the cinemas is polarized light stereoscopy which can now project the two images, superimposed over each other, onto the screen at the same time. This method is now making its way into homes via the use of projectors. 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. Projectors are currently the best way to display the images so you will need to buy a silver projector screen to get the best effect. A silver screen is needed to keep the light polarized so the image remains crisp and clear.
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. Viewing angles are also greater giving you the ability to have a larger and more widely dispersed audience. If you use shutter glasses you can expect about a 20% reduction in brightness. You get a much brighter image with polarized lenses as they only block about 10% of the light.
This article has been written by the author, Alex Blaken. Should you require any more 3D Cinema please visit his 3D Movies resources!