It is the end of the day and I have managed to finish all of the colour corrections for my film.
I followed the same processes mentioned in my last blog post, using different nodes to edit different things.
Time lapse of colour correcting scenes.
Noise Reduction:
A problem that I came across while editing was the amount of noise in my clips. As most of my clips were filmed in low light, at night while my subjects are watching TV, it means that there is quite a lot of noise in my clips.
‘Video noise is typically a result of digital gain and appears as unwanted grain or artefacts in the video image.’
-Apple (2022), Reduce video noise in Final Cut Pro, Available at: https://support.apple.com/en-gb/guide/final-cut-pro/ver7d031487b/mac#:~:text=Video%20noise%20is%20a%20common,artifacts%20in%20the%20video%20image (Accessed 8/5/22)
I didn’t know how to sort it out since I am new to Resolve, so I watched a YouTube video on how to fix it.
Attempt 1 at fixing noise reduction:
Using the things I picked up on in the YouTube videos I watched, I wanted to try and reduce the noise in my clips.
This was before I realised I needed to pay for the studio version of resolve to access these features.
I thought I’d share the process I went through anyway, since it was interesting learn about new features.
Process:
First I added a new node, before the previous three mentioned in my previous blog post, and then went into the motion effects panel in resolve.
There are three different sections: Temporal NR, Spatial NR, and Motion Blur.
Screenshot showing motion effects panel in Resolve.
Temporal noise reduction analyses the clips across frames to separate noise from detail. (It tracks moving objects to exclude them from the noise reduction).
Spatial noise reduction reduced fine grain, high frequency noise that temporal NR can miss.
And motion blur has nothing to do with noise reduction, it just blurs moving objects.
Below shows the settings I used to help reduce the NR in my shot.
Screenshot of settings chosen.
The number of frames is which the noise is going to be averaged. A higher number is more accurate, but can take longer and it can produce artefacts in the image.
Motion estimation type is for moving objects. ‘Better’ takes more processing time but it is.. better, and since there is movement in my clip, it’s the best option to use.
Motion range = speed of objects in the video. I chose large because there is quite a lot of movement in the clip.
Increasing Luma and Chroma values makes the NR more aggressive, but this is when I realised I couldn’t actually use that effect.
Attempt 2:
I then had to search for more videos to see whether it was possible to remove the noise without having to pay for the studio features, and I came across a few videos.
This method didn’t use the colour correction panel in Resolve but instead the Fusion Panel which I haven’t used much of, but the video I watched explained the process pretty well.
First I selected the clip I wanted to edit, and by pressing Shift+Space Bar, added a Remove Noise effect onto the clip.
When you click on the clip in the viewer, and press R, G or B, it will cycle through the different RGB channels to see where the noise is most.
RED:
Screenshot showing noise in the red channel.
GREEN:
Screenshot showing noise in the green channel.
BLUE:
Screenshot showing noise in the blue channel.
Screen recording showing me playing the video and seeing the noise in each of the channels.
The above screen recording shows that there was most noise in the blue channel. There was a lot of noise in all of the channels (but we already knew that), but blue was significantly the worst.
Doing something about it:
So first off I went to the features on the side of screen (Softness red, green, blue), which are used to soften the grain in the actual channel, and then bring back the details using the detail red, green, blue sliders.
It is a balancing act trying to remove as much grain as possible while also keeping the detail of the image and that is something I couldn’t manage to do.
Screenshot showing sliders in Resolve
Time-lapse of the process of removing noise from footage.
As you can probably see from the video, as I was sliding the softness sliders all the way to the right, but even at the maximum point I could still see the grain. This meant I had to make it even softer than the maximum point, and therefore leaving the image lacking all of its detail.
You have to balance removing grain with having enough detail, because the more detail you add back into the image, the more grain you’re adding back in as well.
I think my shots were just so poorly lit (completely my fault), that there is no way I can remove all the noise from the image without sacrificing the detail.
At the end of the screen recording you can see me turn off and on the Remove Noise Effect, and the before and after in terms of grain look exactly the same, the after shot is just more blurry.
Final Film:
However, below shows the final film after correcting the colour in all the scenes.
Final film with colour corrections, no NR.
Conclusion:
Overall, I am going to have to think about other ways to deal with this problem, as I think the grain in the film does look horrible, but I don’t want to sacrifice detail to get rid of it.
References:
Ripple Training (2021), Noise Reduction in DaVinci Resolve 17, Available at: https://www.youtube.com/watch?v=kyad5n1hKUU (Accessed 8/5/22)
CB Super (2021), Remove Noise in DaVinci Resolve (Free), Available at: https://www.youtube.com/watch?v=ZUX0baWDbZ0 (Accessed 8/5/22)
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