So let's go back a bit and look at higher frame rates, what are the benefits?
Right, well if you look at the history of frame rates and frame rate means the
amount of pictures you take per second. So initially in the old silent movies
black-and-white movies, we used to film in 16 frames a second this frame rate
was increased to 24 frames a second for what we call conventional cinema nowadays,
because they added audio. So most of the movies that you watch and if you ever
look at settings on TVs they're capable of handling this 24 frames a second. Now
the advantage of increasing that frame rate is to capture more date. So we know
that the Hobbit trilogy that was directed by Peter Jackson, he filmed
those three movies in 48 frames a second. So basically he's taking twice as many
pictures per second there's twice as much film going through the camera per second.
The advantage of that is obviously that you capture more data, the other thing
that it does is actually alleviate three problems there are three major problems
when you're filming. One is motion blur, one is strobing and one is something
called a large area flicker. You touched on colour spacing why is that important?
Well colour spacing as I mentioned before - when you're delivering an HDMI signal
like this UHD resolution and higher frame rates there's lots and lots of
data and we're limited to the transmission of this data by the cables
or the transmission system we use. So an HDMI cable you limited to certain amount
of data speed and the same over HDBaseT which is the system we use to deliver
HDMI over cat. So what we've done or what the technology has been released is
something called 420 colour subsampling. The way to think of it is
this - that every pixel on a screen has two attributes or two values. One is its
luma value which is basically how black or white the pixel is which gives you
detail. The other value something called chroma value and that basically is what
colour it is. If you remove the chroma data from an image you end up with a
black and white image. If you remove the luma value you actually get no image
because you've got no detail. Now because the human eyes a lot more sensitive to
black and white than colour what you can actually do is cheat on the colour
spacing. So you can actually share colour across pixels. So actually although we
see the detail, we don't notice that some pixels should have their own individual
colour. We actually share and spread colour across more than 1 pixel. Now we're
using something called 420 colour sunset subsampling - you basically reduce the
amount of chroma data to about fifty percent and this is very important
because obviously we need to deliver HDMI signals across HDBaseT in our
industry. And HDBaseT has a maximum bandwidth delivery speed of eight
gigabits per second. If you filmed and used full-colour just like 4-4-4
which is not subsample, there's way too much data. Your looking at something like
17.82 gigabits per second at high frame rates at 60 Hertz frame rates. So
by using 420 code subsampling that's reducing that amount of data to
about half of it. So all of a sudden your down below the maximum bandwidth speed
of HDBaseT and you can drop it to about 7.7 / 12 gigabits per second. So
now you can deliver high frame rate image at UHD with this 420 subsample colour.
Now motion blur that occurs for example if you're
filming a football game when there's a ball goes across the camera and it looks
blurred. It's very similar to when you're taking a picture and you jar the camera
the last second you get a blurred image. To alleviate that what they tend to do
is to reduce the shutter speed when they're taking these pictures. So they
take the same number of pictures per second with very short ones. What happens
then is you create something called strobing where it looks like the ball
has jumped across the screen and on bigger screens that's more apparent. So
by increasing frame rate, increasing the number of pictures taken per second you
alleviate those two problems. The third one which is a bit technical which is
called large area flicker. This occurs on your peripheral vision on big screens
and bright areas where the the bright picture fuses the frame rate. Once
again by increasing frame rate you reduce that. So you've eliminated three problems
and you've captured more data to make the picture more lifelike. Now as far as
cinema goes, unfortunately that's not what we like because in this movie The
Hobbit they have filmed and shown this movie in 48 frames a second in several cinemas
in London. And apparently most people are a bit shocked because it's incredibly
lifelike and it's slightly unnerving because we're so used to watching movies
in 24 frames a second. 48 frames per seconds for us makes it look asif
we're standing next to the camera watching the movie being
filmed. As opposed to watching it as suspected. So in cinema we're not so sure
this high frame will work. However what you must remember that the whole
point of 4K - what's driving 4K is sport. That's exactly what we want with sport,
we want it to be more and more lifelike. So by filming in higher frame rates, we
get more data. We eliminate those three issues and we get this more lifelike
image. So higher frame rates coming in but there's a price to pay because that
higher frame rate is capturing more data and therefore requires a lot more
bandwidth to deliver that signal.