Building the perfect TV has always been an impossible task for the bigshots of the electronics world.

While the current batch of flatscreen efforts are brighter, thinner and better than ever, the problem is that there's always room for improvement.

The contrast ratio can always be improved on as well as aspects like colour reproduction, pixel density, resolution, brightness, thickness and bezel size, to name but a few.

And that's not even mentioning the new challenges that inevitably get thrown up as new technologies are invented.

The current headache facing Sony, Panasonic and the like comes in the form of a new phenomenon found in 3D TVs called 'crosstalk'.

How it works

To create the illusion of 3D on a two-dimensional screen, a 3D TV needs to show two separated images, one for each eye.

Current 3D TVs show the two separate images sequentially - so very quickly one after the other. Active shutter 3D glasses are then synchronised by the TV's infrared emitters, and close and open the shutters many times per second, in time with the images.

When the left eye image is shown, the right eye shutter closes and so forth.

But if the two images are not separated perfectly, part of the right eye image will be seen by the left eye and vice versa. And this causes crosstalk - a sort of blurry ghosting effect around some edges in the picture.

Crosstalk can occur if the liquid crystals in an LCD panel do not switch fast enough from bright to dark or vice versa, or if the phosphor cells in plasma panels have an afterglow that lasts too long.

3D glasses can also cause some crosstalk if they're not precisely synchronised with the TV or if they are sensitive to an inclination angle.

At best, crosstalk can be an unwanted distraction, while at its worst it can completely ruin the 3D effect and make a 3D picture unwatchable. And it's the battle to eliminate crosstalk from 3D TV pictures which is currently occupying the minds at the big telly manufacturers.

So if you're thinking of buying a new 3D TV, how do you ensure that you buy the TV with the least amount of this disturbing crosstalk?

Many people believe it comes down to that age-old choice between LCD and plasma. So which telly tech is best for 3D?