All about 3D glasses: Active and Passive glasses for 3D TVs
Over the years, it is not only the geometric dimensions of TVs that have changed but also those of the images themselves. After HD and Smart TVs had become household names, the next novelty to hold the viewer captive is 3D TV. Similar to the 3D movie experience, to watch 3D TV one needs to sport 3D eye wear as well (There are some TVs that give 3D images without glasses, but this technology has not yet dropped in the market). This article explains two variants of the 3D glasses : Passive and Active 3D glasses. Read on to know more.
The main advantage of passive 3D glasses is that they do not require power and are also not very costly. Active 3D glasses require power. Yes, they have batteries in them to draw power from. Coming back to passive glasses, here are 2 types, anaglyph and polarized. Anaglyph glasses commonly seen with one red and one blue glass use colour to show 3D images. This is not the best way to view 3D as some of the color information is lost.
There are 2 types in polarized glasses, they are linear and circular polarized. Linear glasses are required to be kept at a vertical position for viewing a 3D image. Any movement of the glass will not render the 3D image properly, Circular polarization does away with this problem but it requires a special projector and filters and will not be used on 3D televisions.
Active glasses require power to work. Shutter glasses are the most commonly used active 3D glasses for viewing 3D content, they use LCD lenses that are made to alternately open and shut each lens to show each eye a different image. The major disadvantage with these glasses is that separate images for the two eyes are not given simultaneously. This reduces the frame rate. Therefore 100 fps video will look like 50 fps. There is no loss in color information though.
Rohit currently heads the team at Gadgetronica. His interest in gadgets and technology is as old as mobile phones themselves. Rohit keeps on top of happenings in the consumer electronics segment in particular and tech world in general.
14 October, 2012