As you’ll know by now, 4K or Ultra High Definition as some manufacturers call it, is the coming thing in TV. It means resolution that’s four times current Full HD. So instead of 1920 x 1080 pixels, it manages 3840 x 2160 – that’s over 8 million pixels in total.

It is picture quality that has to be seen to be fully appreciated, and has a level of realism that the screen makes you feel you’re simply looking through a window. More so if there’s landscape on screen, less so if you’re watching 2001: A Space Odyssey.

Anyway, this is technology you can buy today. There are several models in the shops, one from Sony, one from LG. Both cost well over £20,000.

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In other words, it’s very pricey and that size is way too big for most living rooms.

Sony is the first company to solve this problem, which it’s done by introducing smaller screen sizes. Its 55in and 65in X9000A 4K TVs – on display at the Consumer Electronics Show last week in Las Vegas – will be available by the summer, at considerably lower prices. Though they still won’t be cheap.

After all, this is amazing tech that is instantly recognisable as being leagues ahead of everything we have at the moment. Blockbuster movies are shot in 4K, so they’ll look particularly impressive on these screens.

Because that’s the other problem with 4K: there’s no content available. As Steve Withers, Assistant Editor at avforums.com explains: “While 35mm film doesn't actually have a pixel structure because it's a photo-chemical process, its resolution is equivalent to about 5K. That means all those films shot on 35mm over the last 100 years will look fantastic when converted to the new 4K format and most film restoration is now being done at 4K resolution. People seem to think that only films shot on 4K digital cameras will look good in 4K but there is in fact a vast back catalogue of films just waiting to be rediscovered when 4K goes mainstream.”

So it exists, but there’s no easy way to deliver it. Blu-ray and DVD have much lower resolutions and capacities that are too small, so they won’t do.

Sony seems to have addressed this issue, too. At the launch of the X9000A TVs, Sony announced that it would provide customers with access to seven 4K movies on “the world’s first 4K Ultra HD delivery solution complete with pre-loaded native 4K entertainment” according to the company.

This uses the 4K Ultra HD Video Player, which might mean supplying customers with a server or some kind of download system (though you’d better make sure you don’t have a download cap on your broadband).

On the other hand, there’s always upscaling. That’s where lower-resolution images are made to look better. This is often pretty dodgy, but the chip in the 84in Sony TV is astonishingly good. In behind-closed-doors demonstrations, Sony’s engineers showed upscaled pictures which were almost indistinguishable from native 4K content. Expect the 55in and 65in models to have upscalers to match.

This quality of upscaling is essential as nearly everything you’ll watch will be at lower resolution. Sony’s image processing has been consistently masterful over the years, so expectations are high.

Sound on the Sony TVs should also be much richer than on most flatscreens thanks to the large side-mounted speakers (though they do require a bit more living room space).

The truth is that in 10 years’ time we may well all be watching 4K TV just as often as we now see HD content. But we’re not there yet. Still, if you’d like to see the highest-resolution picture available, these TVs will be worth saving up for.