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Does 4K fit?
by Bob Pank
A s we head once more to NAB you may wonder what this year’s big thing will be. I put my
money on 4K. As I write there must be many exhibitors polishing up their ‘4K solution’
message, ready for their customers at the show. With the extraordinary situation of
screens costing more than cameras, a viable business model clearly remains far off. But, to be
fair, the technology has to start somewhere and screens and cameras seem to be the genesis. In between
there has to be a production and post workflow, as well as a delivery system. Hopefully we will see a whole lot
more of that in Las Vegas; otherwise 4K will not be flowing anywhere soon.
The talk is all about 4K for TV. Its image size of 2160x3840 sits midway between 1080x1920 HD and
4320x7680 originally called Ultra High Definition Television, and later Super Hi-Vision, by its inventors at NHK.
In recent months both 4KTV and SHV have been bundled under the UHD banner, which seems unnecessary
and will cause confusion. (For reference, in the digital cinema world it's 4K is 4096x2160, a 2x2 version of its
2048x1080 (2K) – both slightly bigger than TV’s 2K and 4K.)
With 4KTV being in the mid-size between HD and 8K UHD, it could have a serious identity problem. What
is it for? Is it TV – the thing we watch at home – or cinema with a huge screen and dedicated viewing area?
With digital cinema making fantastic progress replacing film and bring much improved quality and reliability,
just it's with 2K-sized image, why should we want four times that picture detail to watch in our homes – most
of which are smaller than cinemas? This is a matter of screen size, real estate and the way we watch TV and
movies. Many HDTV viewers find 42-inch
screens work well for them. Logically,
it follows that 4KTV, with four times
the picture area, should be viewed
on an 84-inch screen, and I’m sure
there will be plenty of these to view
at NAB. Sony showed a very well
produced show reel at IBC where you
could look, and then look closer and
see more and more detail. You could
look around the picture and study the
detail; a rather different experience to
SDTV where the camera selects the
one object you are meant to look at.
HDTV allows us a bit more freedom
to look around. That freedom is
dramatically multiplied in 4KTV – and
even more so in 8KTV... on your 168-
inch screen, perhaps?
It’s all very well admiring the huge
screens in the vast halls of the Las
Vegas Convention Center but think
about it, how would it look in your
sitting room, or wherever you watch
your TV? Maybe you think you’ll
manage with a smaller screen – and
why not? The 84-inch LED models
retail for around £20,000... and so are
clearly not aimed at the mass market.
I’m sure they will come down but it
surely won’t ever get low enough to
appeal to the wider consumer market.
Fortunately Harrods was showing a
range of 4K screens. This was a rare
opportunity to see many different
brands side by side. Yes all the 84-
inch models looked fantastic and the
super rich were, reportedly, buying.
However the screen that really stood
out was hailed by LG, its maker, as
‘The World’s First 55-inch OLED TV’.
Not only did it have beautiful blacks
and very high contrast, but pretty
much a 180-degree viewing angle.
The screen was just 4mm thick,
including its carbon fibre backing, and
the whole thing cost just £10,000.
This is a great improvement, not just
for the better contrast and picture,
but it did the job in a smaller package
that many more people could
accommodate at home.
To see all 8.2 million of 4KTV’s pixels
you need to get sufficiently close
to the screen, but not too close. A
survey in the USA found that HD
viewing distance was generally
around 2.7 metres (9 feet). This may
be more down to the furniture than TV
technology! My web research threw
up widely varying recommendations
but the one I trust most is at
videograndpa.com showing test
results from NHK, and their graph
indicates a 1.5 x screen height (H) is
best. The 4K screen size calculator
shows recommendations from NHK,
SMPTE and THX that widely vary.
For example, for viewing at 9 feet
it indicates 146, 73 and 90-inch
screens respectively. Of the three,
NHK’s is based on actual experience
and so I think is nearest to the best
result. But even taking the smallest,
a 73-inch screen is still a monster.
Either we retain our 9-foot distance
and endure the monster, and its
costs, or we move in a lot closer.
The probability is that we’ll buy an
affordable size and sit 9 feet away and
not see the full detail of 4K.
Viewing at NHK’s recommended
distance to the screen creates a wide
viewing angle, somewhere about
36 | TV-BAY MAGAZINE