Television is evolving. 4K Ultra HD is rewriting the rulebook when it comes to image quality, and in the process is beginning to fundamentally change everything from programme production to distribution technology.

4K TV sets are now available from most of the major TV manufacturers, but they're merely the tip of a very cool technology iceberg. So what, we hear you ask, is 4K really all about?

Read on for greater clarity…

What is 4K?

The headline fact is simple and dramatic: 4K Ultra HD TVs (also known as UHD TVs) deliver four times the picture resolution of 1080p Full HD, that's eight million pixels compared to two million pixels.

What that means in terms of potential image clarity is more fine detail, greater texture and an almost photographic emulsion of smoothness.

But this is just for starters. Prior to a roll-out of TV services, broadcasters are working out what else they can upgrade under the 4K banner. In the UK, a working group chaired by the BBC and BSkyB are mulling over every possible tweak, from higher frame rates to greater contrast and a wider colour spectrum.

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Talk to the engineers steering this 4K broadcast bandwagon and they'll tell you everything spec-wise is up for grabs. If this indicates to you that the 4K standard is anything but set in stone, you'd be correct.

Ultra HD is going to be a work in progress for years to come, but that doesn't mean you should wait for the dust to settle before improving your image.

Difference between Ultra HD and 4K

4K Ultra High Definition is actually a derivation of the 4K digital cinema standard. However while your local multiplex shows images in native 4096 x 2160 resolution, this new consumer format is 3840 X 2160.

This is one reason why some brands prefer not to use the 4K label at all, sticking with Ultra HD instead. However, the numerical shorthand looks likely to stick. As a broad brush label it's so much snappier!

Why should I care about 4K Ultra HD?

There are many reasons why 4K should make you rethink your next TV purchase (actually, there are eleven and you can read about them here), not all of them immediately obvious.

Photographers who routinely view their work on an HD TV are seeing but a fraction of the detail inherent in their pictures when they view them at 2160p. A 4K display reveals so much more nuance and detail – the difference can be astonishing. While 3D has proved to be a faddish diversion, 4K comes without caveats. Its higher resolution images are simply better.

The higher pixel density of a 4K panel also enable you get much closer without the grid-like structure of the image itself becoming visible –this means you can comfortably watch a much larger screen from the same seating position as your current Full HD panel. Currently all available 4K Ultra HD TVs are in excess of 50-inches.

Projectors

While 4K UHD TVs are on the fast track, the same can't be said for video projectors. Only Sony offers 4K models, the high-end quasi pro VPL-VW1100ES and the home cinema friendly VPL-VW500ES.

Currently there's no consumer 4K solution for LCD, D-ILA or DLP projectors, although that's likely to change in 2015, when Texas Instruments is expected to begin shipping its first 4K DLP chipset for home hardware.

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How expensive is an Ultra HD TV?

The first wave of 4K TVs were large, really large. Both Sony and LG launched with 84-inch panels, the KD-84X9005 and 84LM960V respectively.

Consequently, they were saddled with price tags in excess of £20,000/$30,000. Not to be outdone, Samsung weighed in with the 85-inch S9 at £35,000/$55,000, clearly aimed at footballers and oligarchs!

However, prices have fallen dramatically as screen sizes have shrunk and brands have predictably embarked on a tit for tat price war.