A 4K Future Filled With Fixes, Fudges And Football

Duncan Payne, Sales Manager at WTS Broadcast, assesses the state of play for 4K broadcasting and, with the World Cup in Brazil upon us, the particular difficulties that sports coverage throws up.

Having spent the past few days enjoying the delights of Dublin with one of WTS' key supply partners, Ross Video, it was interesting to see how little talk there was amongst fellow delegates – and Ross themselves – around 4K.
It was touched on briefly in the switcher seminar, ticking the 4K box and we moved on. All Ross switchers, except the entry-level Crossfire unit, can accept 4K and deal with it in the same way as most equipment manufacturers are – in quad HD; that is, four HD signals on four BNC connectors. It seems a sensible solution for the time being, at least until a 4K standard is established.
But standard 4K practices are precisely what we have not yet achieved, with work-arounds needing to be found at almost every turn. And even the term 4K is a little misleading, as it really should be called UHD – Ultra High Definition. Four times 1920 x 1080 = 3840 x 2160 if my 'A' level maths is correct, whereas 4K is really 4096 x 2160.
It is in the world of sports broadcasting, however, that the real difficulties of shooting in 4K with the current technology come to light.
To allow the use of the current inventory of box and barrel lenses ubiquitous at every sporting event, an adaptor is required to mount the B4 2/3" lenses to the PL mount cameras. This 'fudge' is hardly ideal and creates problems of its own. The unforgivingly high resolution makes long lenses unusable towards the long end of the zoom – the presence of the adaptor magnifies lens aberrations that are there but less noticeable at HD with no adaptor.
Another feature of large sensor cameras is the shallow depth of field they create. This effect, so greatly desired by film and drama directors looking to control the narrative of the story, is exactly the opposite of what a sports viewer is used to, or wants. Here the solution lies in the considerable skills of the camera operators, negating the anticipated need for a focus puller to keep the desired shot in focus.
A more pressing issue is that of frame rate. On all but the slowest pans at UHD quality, the resolution is just too good, with the resultant image flicker unacceptable to the viewer. The obvious answer is to increase the frame rate, with frame rates of 120FPS regularly shot. But the equally obvious problem this raises is that there is now even more data to pass through traditional copper cable.
Whilst this data transfer can be done using the quad HD method, this does severely reduce the capability of the infrastructure. The Telegenic truck that covered the 2013 FIFA Confederations Cup in Brazil had a Sony vision mixer configured at a staggering 8ME, but the quad HD requirement effectively reduced it to a 2ME mixer. Clearly the long-term fix is to move to a fibre environment where the bandwidth issues of copper cable are removed.
In the mid-term, the most likely solution is a hybrid one. A 4K workflow can be employed for wide shots where great detail of the crowd and the whole playing surface can be enjoyed, while tight shots such as player cameras that capture the emotion of the players will still be shot in HD – which, I should add, hasn't suddenly become redundant overnight.
Camera choice generally is also interesting now, with a growing range of 4K options following announcements at April's NAB, including the AJA Cion, Blackmagic URSA and the Panasonic VariCam. The latter is particularly clever as it is effectively one recorder with either a 4K PL-mount single sensor or an HD 3 x 2/3" sensor camera head.
ARRI are still keen to argue that their Alexa – and now the Amira – shows that there is no need for anything higher than HD, and no doubt will continue to argue this point up until the moment that they release a higher resolution option themselves.
But it will be consumer demand for UHD that will ultimately be the driving force for whether higher resolution production will work or not, just as the resistance against wearing glasses put a halt to the most recent resurgence of 3D.
1.1m UHD screens shipped globally last month, compared with an average of under 150,000 per month in 2013. Yes, there were similar figures quoted for 3D screens not so long ago, but those articles omitted to mention that no one was buying the screens because they offered 3D. It was an extra feature of HD TVs which falsely inflated the apparent demand for 3D. The UHD figures seem more credible to me, and this huge clamour for 4K will allow manufacturing costs and therefore sale prices to fall further, thus prompting more sales and so on.
This summer's World Cup in Brazil will be a great showcase for the technology as all these new screens will be fed with the very best content. So we can look forward to seeing glorious detail of every hair on the players' heads. Which is unfortunate for Mr Rooney, but great for Mr Cole as he watches from his armchair. Though with Sony's 4K coverage only planned for games in Rio's Maracana stadium, England quite conceivably need to reach the final to grace our screens in full 4K glory. No, I'm not holding my breath either.

The article is also available in RFV online.

(IT/JP)