3D TV

 How does 3D TV work?
Your brain creates a sense of depth by combining the slightly different perspectives from the left and right eye of the same object or scene into a 'merged image' that includes depth information.  Delivering the two different images on a single two dimensional screen to the viewer is a challenge as there is only one view available to both eyes.
3D projects both a left and right image onto the same screen, and then the glasses that you wear filter out the correct image to each eye, to create the sense of depth of real life.
How are 3D images captured?
3D starts with recording content the way that our eyes see it - from two different perspectives. Two HD cameras are used in a special camera rig to take aligned left and right images of the chosen scene so what you see at home is exactly what the cameraman sees whether he's on the touchline of a football match or in the heart of a car chase in a movie.
The images then make their way through Sky's broadcast infrastructure where they are compressed and positioned side by side in a single HD frame.
How are 3D images broadcast?
3D is broadcast using a normal HD broadcast channel, over existing infrastructure which means you can enjoy 3D using your Sky+HD or HD satellite receiver, provided you have a 3D ready TV. 
How are 3D images viewed?
There are two different 3D TV technologies coming to market now.
The first, polarized screens, project both the left and right images onto the screen at the same time, and then a special filter on the glass polarizes the left and right images differently, such that your 3D glasses then use a different left and right lens to filter the correct image to each eye.  Your brain then does the rest.
Active shutter glasses alternately 'block' one eye and then the other in sync with the TV, which is alternating left and right images on the screen at a very high rate (usually a minimum of 50 frames per eye per second).  This is fast enough that the brain sees no gaps, and again, takes the two different views from left and right eyes to merge them into an image with depth.
The best way to choose the one that suits you is to go to your local retailer and take a look. 
Can 3D TVs only be used to watch 3D content?
The new 3D ready TVs coming into the market will all be fully HD ready, so you can still watch HD and SD channels.
Active v Passive 3D glasses explained
Active glasses contain LCD lenses that alternately 'black-out' each eye depending on whether the right or left image is being displayed on the screen.  They are referred to as active because they require a battery to operate the LCD lenses. The shuttering occurs so rapidly that you don't see the shutters just the amazing 3D picture. 
Passive glasses use polarisation to separate out the left and right image.  They are referred to as passive because the glasses do not require any power to operate them. These work with polarised TVs that use circular polarisation to deliver the two images to the viewer.  The TVs have a polarized filter integrated into the screen, and when switched into a 3D mode, the filter orientates the light emitting from screen differently for the left and right image.  When you put on the passive polarised glasses the left lens has a filter that blocks out the right image and right lens has a filter that blocks out the left image.
One important point to consider is the cost of replacing broken or lost 3D glasses.  Active glasses will cost more than polarised glasses due to the additional technology they use.  Active glasses will also occasionally need a new lithium battery (similar to a watch battery) when it runs out.
Will I be able to record 3D programmes?
Yes, with either an internal or external hard disk drive attached to your HD satellite receiver