3D TVs buying guide
Instead of just watching films, TV and sports you can be really ‘in them’, with action that leaps out of the screen and a feeling of true depth to each shot.
If you've seen a recent 3D cinema film then you already know what you can expect at home. That's because the effect is created in an identical manner to that in the cinema. But instead of using a projector that costs hundreds of thousands of pounds, you can enjoy it on a 3D-ready big-screen TV.
How are 3D pictures created?
3D images are created by copying the way your eyes work. The left eye and the right eye see slightly different versions of the same scene in front of you, because they're looking at it from different angles. Your brain takes the two images and works out how far away objects are from it, giving you 3D vision. 3D TV is exactly the same: each eye is shown a slightly different image of the same scene taken from different angles, and the brain thinks it's seeing the 'real' world. There are two ways TVs can do this:
- Passive 3D: the first is often called 'passive 3D', because the glasses used don't require any power. Both the left and right images are shown on screen at the same time, but a filter in front of the TV is configured to polarise the light for each image differently. By wearing similarly polarised glasses, the right eye can only see the right image and the left eye can only see the left one. Because only half the screen is used for each image, though, the picture isn't as sharp as HDTV.
- Active 3D: the superior and more common technology is often called 'active 3D' or 'active shutter', because the glasses need to be battery powered to work. Active 3D TVs have very high refresh rates, showing 120 images a second or more. The entire screen is filled with the image for the left eye for one frame, then replaced by the right eye image the next and so on.
To separate the images out, you wear a special pair of 'active shutter glasses'. Each lens has an electronically controlled filter that can be turned off and on and off at the same speed as the TV refreshes the frame. By blocking out the vision to the right eye while the image for the left is on screen, and vice versa, the brain sees the two angles it needs to create a 3D image. Because the entire screen is used for each frame, the picture is much sharper than passive 3D.
Three steps to a 3D-ready TV
1. Get a 3D-ready TV
New 3D-ready TVs are now available from big names such as Sony, Samsung, Panasonic and LG. These come with special hardware and glasses to enable the 3D effect.
2. A 3D capable box
Currently the PlayStation 3 and some Blu-ray players can be updated to play Blu-ray 3D films and games. Sky have launched 3D channel Sky 3D, which is available on its Sky+ HD box to Sky World HD customers.
Enjoy films, games and more
Blu-ray 3D movies and PlayStation 3 games are available to buy and Sky is already broadcasting 3D programmes ranging from sport to the arts to Sky World HD Pack subscribers.