Ultra HD unveiled: Behind the scenes of the UK's first 4K live trial
3rd Sep 2013 | 11:00
TechRadar given exclusive access to Ultra HD trial
The problem with a lot of the latest television technology is that, at its heart, it doesn't actually make watching television better.
Something like 3D is fun enough but would you choose to watch the finale of Breaking Bad or the World Cup final in that format? Smart functionality is nice but doesn't really enhance the actual content significantly.
If we're being entirely honest, the most significant improvement in televisions of late has been the arrival of HD, which is why - even at this early stage - we're entirely prepared to be excited about 4K.
4K or Ultra HD, for the uninitiated, is what HD dreams of being when it grows up. With a resolution of 3,840 x 2,160 it offers up four times as many pixels as Full HD 1080p.
That means four times the clarity of a 1080p picture, bringing a clearer, more vibrant picture that becomes significantly closer to looking real.
So we jumped at the chance when Sky invited TechRadar to its Osterley headquarters to watch an important test broadcast of 4K. We've seen plenty of 4K picture tests in the past, and we've even taken a look at some sport from the BBC filmed in Ultra HD.
But Sky were testing 4K using their existing infrastructure, not the boxes you have in your home, but the system that underpins their satellite broadcast platform. And that gave us unprecedented access to how 4K live broadcasts are actually going to look and feel.
And what better way to offer up a true test of Sky's service than to showcase a live Premier League match?
The company is at pains to point out that these tests do not necessarily mean that we will see Sky Sports Ultra HD any time soon, but it's clear that the company is taking this next evolution of television incredibly seriously.
The match chosen was West Ham's match against Stoke City at the Boleyn Ground (Upton Park to the majority of us). TechRadar was the only publication outside of Sky to be watching the broadcast on an 85-inch Sony 4K television worth a little more than a family car, with filming done on four Sony 4K cameras (and an upscaling 1080p camera as part of the test).
Tony Mills directed the game for UHD - and he knows a bit about using new technology to show off football having been in charge of Sky's first ever Premier League match, the first broadcast in HD and the first 3D one to, ahem, boot.
What is truly remarkable about the entire broadcast is just how close it feels to readiness. With the early 3D tests and trials there were huge problems on show, but the extra resolution being offered up by 4K seems far less prone to pitfalls and issues.
The picture was being sent through the system as four 1080p pictures which are stitched together then routed through, what for now is, proprietary Sony kit and into the television using an as-yet unratified HDMI version to the television.
Given that Sky's current HD service is 1080i, that means each quarter of the picture is using twice the bandwidth of a typical broadcast, making it, in total, 8 times more data being transferred to populate more than 8.2 million pixels that make up the television.
What does that mean in terms of viewing experience? Well, the tech demos that we have seen to date at various shows have been polished for the audience, graded and checked for problems before we have had a chance to check them out.
Sky's live pictures are obviously live, raw and therefore we fully expected to be a little disappointed.
Delightfully, we were wrong - even though lessons are still being learned, the clarity of the pictures is phenomenal. If anything the impact of moving from HD to Ultra HD is even more staggering than the transition from SD to HD, it's that good.
A great example was handily provided by the sprinkler system in the pre-match sunshine; the hazy partial rainbow that appeared on the UHD screen was nowhere to be seen in HD. It would be wrong to suggest that 4K pictures are just like being sat there, but at times it is easy to kid yourself you are looking through a window.
Every crowd shot, even from a distance, does not seem to diminish the details of people's faces, with sometimes amusing consequences you can lip read what the fans behind the managers are saying. You can see every nervous tic and irritated glance coming from the dugout, and these are just the incidentals to what is going on on the pitch.
Given the limited number of cameras (to put it in context the four UHD rigs and the supplementary 1080p camera being upscaled fall some way short of the incredible 24 cameras that were pitchside at Anfield the day afterwards for Liverpool v Manchester United) Jermaine Pennant's late winner from a free-kick, did not have enough angles to do it full justice, but the wide shot was perfect to see just how much quality it took to bend the ball past the wall.
Essentially, the Ultra HD seemed to allow the director to tell more of the story. By necessity and choice a lot less tight shots of players from the shoulders up were shown, but the replacements gave you more of the context of the player without losing the effect of seeing their face.
There are still issues that Sky (and the whole industry) needs to work through; the 50 frames per second that the company feels is appropriate for live sport is short of what the film industry has suggested, just one of several standards based discussions that need to happen and the broadcast quality kit is rarer than hen's teeth. In fact Sony have lent Sky huge amounts of the kit necessary to do these trials - including the four 4K cameras used at Upton Park.
In terms of what we saw, dealing with shadows on the pitch caused issues - although even the 90 minutes of test saw vast improvements, and finding the right focus was occasionally problematic.
Chris Johns, Sky's Chief Engineer and a man overseeing the test with all the pride of a new father, explained to us that Sky's enthusiasm for the product was huge but that the nascent Ultra HD market simply needs to catch up before any broadcaster on the planet can consider launching a 4K channel.
Which given TechRadar's experience is a real shame, because the lack of 4K content is going to be a key factor in holding up the television sales that will fuel the move to mainstream.
But most of all, it's a shame that the mass market is not getting the chance to see just how powerful 4K Ultra HD pictures are compared to what they are used to.
Even with bigger screens you can sit much closer because of the greater pixel density so you can be even more drawn into the action, the level of detail brings the picture to life in a way that's difficult to do justice to and the sharpness of the colours make the whole thing a pleasure to behold.
Sky simply cannot put a timescale on when we will see a Sky Ultra HD channel, there are too many factors outside of its control, but the excitement from the broadcaster at the prospect of 4K pictures is infectious.
The upshot of the demo is that Sky, and therefore other broadcasters worldwide are already capable of making first class live 4K content. And that should make us all more confident that Ultra HD is arriving fast.