ISE this year was, once again, home to the latest developments in screens and projectors, with exhibitors showing off images of unprecedented quality as they continue to push the boundaries of the technology. Ian McMurray asks where it will all end?
It used to be that buying a new TV was a once per decade - perhaps once every two decades – exercise. Now, it’s more likely to happen every couple of years. Why is that?
The answer has much to do with resolution. We bought High Definition. Then we bought Full High Definition. And now, we’re buying Ultra High Definition. The Tokyo Olympics in 2020 will be broadcast in 8K resolution (aka Super Hi-Vision) – so we’ll likely feel we have to trade up again. Where – if anywhere – will it all end?
At ISE 2016, there was much talk about resolution, with plenty of 4K resolution screens to admire. Trade show demonstrations, however, are one thing – but what’s the reality? Unsurprisingly, the answer isn’t 100% clear – not least because not all 4K is created equal…
“4K is absolutely deployable today, though there is a question of 'which 4K?'”, smiles Andy Fliss, VP of sales and marketing at TV One. “Today, we are often still sold UHD (4K30) which is supported by the current HDMI 1.4 chipsets. That’s the reason so many manufacturers have been able to quickly offer it. There was basically no change to their equipment, just a new resolution.”
“4K in all its glory is actually 4K60,” he continues, “and uses deep colour - 4:4:4 - which requires HDMI 2.0 at both the player and the screen end. The colour depth is important to keep an eye on as there are many manufacturers offering 4K60, but only at 4:2:0.”
“The main problem here all boils down to the problem of bandwidth,” adds Fliss. “In terms of infrastructure, 4K can be distributed in uncompressed form but only over fibre. The accepted compression standard for 4K signals is H.265. 4K30 and possibly 4K60 (4:2:0) can be squeezed down a Cat6 cable for 100 metres, but when it comes time to fire up your 4K60 (4:4:4) system, you’ll need to pull cable.”
Franck Facon, marketing and communications director at Analog Way, sees a similar scenario. “Today, 4K resolution is not truly deployed, because there are still many holes in terms of transporting the signal,” he believes. “As we’ve already experienced in the past, when HD resolution was launched, we’re currently experiencing non-coordinated 4K product launches, based purely on the interests of each market segment. The display is the tip of the 4K iceberg; the hidden part is full of issues that need to be solved for pro AV use. Overall, 4K is in a transition phase between 30P and 60P. The spread of HDMI 2.0 and DP 1.2 should allow the first generation of products to be proposed that are compliant with customer expectations. But some problems that we need to solve will still remain, such as network and storage.”
4K is the latest stage in a journey in which resolution has become the headline marker of image quality. It’s important to remember, though – as Fliss and Facon confirm – that there is much more to image quality than just resolution.
“There are several factors which contribute to perceived image quality,” explains Tobias Stumpfl, CEO at AV Stumpfl. “Resolution is one which is easily measurable, and so are frame rate and colour depth. But also, the human eye has an influence: its limited ‘capture rate’ does, in fact, limit the maximum possible resolution which can be perceived, especially in motion pictures.”
It’s also about contrast ratio and brightness. Resolution is a key contributor – but far from the only one. It does, however, have the distinct advantage of being easy to comprehend – a point made by Virginia Cheng, director of business line management, Europe Region at BenQ.
“Technical specification and price are easier to explain to customers,” she says. “Image quality or colour quality are subjective, though, and not as easy to communicate. Manufacturers use numbers to try to quantify what they claim is their product’s superiority – and resolution is an easy-to-market, easy-to-understand number. Anyone can understand why 8K is better than 4K is better than 2K.”
Enrique Robledo, Panasonic’s European marketing manager, has an interesting perspective. “Resolution is just a portion of the image quality perception - but image processing and the quality of the panel are the true drivers of the quality of the display,” he believes. “Our customers first and foremost want a screen that they feel confident will allow them to display products and information first time, every time. For signage applications, high reliability is much more important than a few extra pixels.”