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Hey everybody, Simon Walker here again. OK, Iʼll admit it, I donʼt always shoot
my videos properly. On many occasions I shoot without lights, and in a hurry.
But itʼs not always my fault! Often I have to react quickly to events, or accept less
than perfect setups, just so I can fit into a clientʼs schedule. I don't always have
control over the shoot. And thatʼs the nature of shooting digitally, especially if youʼre
dealing with low budgets, or short deadlines. Or both!
This often means shooting in low light. And as great as modern cameras are at generating
images at low light, shooting without proper lighting will introduce noise into the picture.
Especially in the darker areas, and in areas of flat colour.
And itʼs this noise in the picture that typically motivates me to load up Magic Bullet Denoiser.
Iʼm being motivated by the image... this is a visual improvement I want to make, to
enhance the shot and increase the quality of the image... to make it look better.
But actually, thereʼs a interesting side effect of reducing the noise in an shot, it
brings down the file size in the exported file.
And thatʼs what I want to point out in this QuickTip, how compression is made more efficient
by reducing the noise in your videos. This clip was shot as a test in low light
on a Canon 7D, and Iʼve used Magic Bullet Grinder to convert it from the H.264 codec
it was recorded in, to ProRes, and this is using ProRes 422, or ProRes Standard, which
has a maximum target data rate of around 150Mbps. Iʼve added Denoiser at the default settings
to this test clip in Final Cut. And even at the default settings it does a pretty good
job of identifying and decreasing the noise in the image.
By the way, I go through the various interface settings in the Getting Started with Denoiser
in Final Cut Pro tutorial, which you can find on the Video Tutorial page of the Red Giant
website, so itʼs worth checking out, as you can fine tune the plug-in to analyse and help
remove more stubborn noise. But if Iʼm in a hurry, which letʼs face
it is most of the time, I get great results by using just these two sliders, the Noise
Reduction slider and the Enhancement slider .
As a rule of thumb, if Iʼm increasing the noise reduction, I usually balance this by
increasing the Enhancement slider as well, so as I decrease the noise I can still keep
the detail around key areas. Iʼll switch the filter off and back on again,
and toggle between those two states, so you can see what the clip looks like before and
after Denoiser is applied, and itʼs doing a really nice job of removing the noise in
the face whilst keeping the fine detail in the hair.
And this is great, it can save a shot that I might have otherwise considered was too
noisy to use. But I think itʼs worth pointing out what
removing noise from a shot does to the size of the exported file.
One of the basic principles of digital video encoding, is that the more pixels change from
frame to frame, the more data is required to describe the image, which is the sort of
thing you get when youʼve got lots of noise in the image. The noise takes up more data.
But if you remove the noise, the compression can be more efficient, and the size of your
exported file is reduced. This is a ProRes clip sitting on an HD timeline,
so itʼs got ProRes as the compression codec. And when I export the timeline using File
/ Export / ... QuickTime Movie, Iʼm going to end up with a 1920x1080 file with ProRes
as the codec. And thatʼs exactly what Iʼve done with this
timeline, but Iʼve exported two versions of the clip, one with Denoiser applied, and
one without. So one is the original low light noisy, grainy clip and the other has much
less noise. But have a look at this... the file with reduced
noise is significantly smaller in size than the noisy clip
The noisy clip is almost 400MB in size, and the Denoiser clip is 325MB... and thatʼs
about 30% smaller. This is quite a short clip, itʼs only about
30 seconds long, but a 30% on long durations can be quite a significant difference.
This is because thereʼs less noise in the image and the ProRes compression algorithm
can be more efficient during the encoding process.
The thing about ProRes, is that although it has a maximum target data-rate, itʼs an intelligent
codec, and it tries to keep the file size down as much as it can, depending of course
on the movement and the detail in each clip. So with this technique, as well as looking
better, and being more appealing to the viewer, your master QuickTime movie will have a smaller
file size. And these file sizes can quickly mount up.
I know, file size probably isnʼt the first thing you think about when you see a noisy
clip... But its a nice happy accident to have... or
a nice additional positive aspect of increasing the quality of a grainy shot.
And of course, the better quality your master file, the better it will compress down for
the web and for mobile delivery. You can catch more of my Final Cut Pro tips
and Red Giant Software tips on Twitter.com/simonwalker But until the next time, good luck, and have
fun.