WITHOUT SILY GLASSES 3D TELEVISION

OK, so you want 3D TV, but you don't want to wear those dorky Timmy Mallett glasses that they gave you in the cinema when you went to see Avatar and Up. Never fear: tireless engineers have come up with a design that will let you get that three-dimensional experience without face furniture. (If you want to be showy, it's an "autostereoscopic" system.)



The principle is the same as those 3D postcards that entertained you as a child, where you tilt them from one side to the other and the picture seems to flip. That's known as a "lenticular lens" – officially, an array of magnifying lenses that show different pictures when viewed from different angles. But where the postcard shows you only one image at a time, the lenses on the 3D TVs already in production from Philips and LG show two distinct images, one for each eye, routed through the lenses (which act more like slits pointed in particular directions).

If you ask a 3D-imaging specialist such as NewSight how it does it, it will say that it has "a proprietary technology with numerous patents throughout the world". Fine, but what technology? First, you build a standard HDTV; then you add eight lenticular-style layers on top, which break the image into repeating segments – in effect, four potential points of view for the left eye, and four for the right (which means you get the 3D effect over a wide field of view). Your eyes pull two of these images together and interpret them as a binocular scene, which means that you perceive it as being 3D. It's finicky, though: the lenses have to be aligned precisely over each of the millions of pixels in the screen. That means you're not going to be getting them cheap for quite a while.

There's another catch: some people who have tried the sets over long periods have reported feeling seasick (and not only while watching A Perfect Storm). This is caused by your brain struggling to cope with changes in focus and orientation as whizzing camerawork is a favourite of directors discovering 3D. But don't worry, they'll surely calm down when the novelty wears off.