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Colour banding in 12 bit braw

PostPosted: Sun May 28, 2023 3:01 am
by ktaylor355
Hey everyone,
Can you help me with why my braw footage and render both have imo severe banding, in blacks, greys and skin tones.
It was shot in 6K 8:1 at 48fps.

Here is a link to the video.


I hope you can teach me the error of my ways

Thanks

Re: Colour banding in 12 bit braw

PostPosted: Sun May 28, 2023 3:37 am
by ktaylor355
I should mention my settings,
Non colour managed workflow.

CST gen 5 film,
To rec709
Cineon

Powergrade (2383) film emulation, will post the node tree asap.
Denoised - first node.
Grain added
Banding seems to be there when converted to rec709, but I cannot be sure it’s there in raw, but I’m thinking it probably is.

Re: Colour banding in 12 bit braw

PostPosted: Sun May 28, 2023 5:50 am
by Marc Wielage
Well, everything on YouTube has banding (to some degree) because the entire service is 8-bits. And everything that's uploaded to YouTube gets recompressed, because that's how they manage bandwidth. Here's a link to some suggestions:

https://www.google.com/search?client=fi ... on+YouTube

My suggestion would be to consider adding a bit of film grain to the entire file, and seeing if this "dither" (random noise) helps make the banding more obscure.

Re: Colour banding in 12 bit braw

PostPosted: Tue May 30, 2023 1:50 pm
by Robert Niessner
ktaylor355 wrote:Banding seems to be there when converted to rec709, but I cannot be sure it’s there in raw, but I’m thinking it probably is.


There is certainly no banding in 12bit raw.
I have watched your Youtube sample now on a calibrated true 10bit Eizo monitor and the banding shows exactly where I would expect it from that kind of flat grading and 8bit encoded YT compression.
And if you have watched this then on an 8bit monitor it can enhance that banding too.

Wherever you have added grain - that got lost in the YT compression, too.

Re: Colour banding in 12 bit braw

PostPosted: Thu Jun 01, 2023 1:08 am
by ktaylor355
Thank you, that’s helpful. I need to do a better job with grading to help the process but seems it’s to be as expected.
You mentioned about “flat grading”, what would you recommend to better the grading, this was my first braw grade, so open to information

Re: Colour banding in 12 bit braw

PostPosted: Thu Jun 01, 2023 5:21 pm
by Robert Niessner
ktaylor355 wrote:Thank you, that’s helpful. I need to do a better job with grading to help the process but seems it’s to be as expected.
You mentioned about “flat grading”, what would you recommend to better the grading, this was my first braw grade, so open to information


I am not judging your grading with this - I just described it as a "flat" look (non-contrasty and de-saturated colors) with lots of bokeh you went for and this creates all those soft going gradients which in turn result in banding. This means the 256 available steps are not enough to distinct from one step to the next.

You also have to be careful not to see banding in your footage which would in reality be a result of your monitor's restrictions (I've fallen for this too). But if the banding is real - then you only can fight it by either going 10-bit all the way or add more noise/grain until it gets masked over and can't be hidden through the encoding. Also do less denoising. It is a balancing act.

You also could try to upload a grained 10bit version to YT and see if this gives a better start for their encoding conversion.

If you have used a LUT for the final look, also try to set the LUT interpolation in your project settings to tethrahedral - because this uses higher precision math it might help with the skin tone thing. Could be an edge case.

Re: Colour banding in 12 bit braw

PostPosted: Fri Jun 02, 2023 7:35 am
by ktaylor355
Thanks for that, btw even if you were talking about the grade, I’d be ok with that lol.
Ah that’s really interesting, I’ll keep that in mind.
I don’t have a calibrated monitor, so could be that also.

Thanks again.

Re: Colour banding in 12 bit braw

PostPosted: Tue Jun 06, 2023 5:54 pm
by Hendrik Proosa
ktaylor355 wrote:I don’t have a calibrated monitor, so could be that also.

Any monitoring related issue is easily detected if you crank exposure or gamma up and down. If issue is in data, it won’t shift around. If it is in display chain, problem magnifies or disappears.

Re: Colour banding in 12 bit braw

PostPosted: Thu Jun 08, 2023 11:28 am
by ShaheedMalik
Robert Niessner wrote:
ktaylor355 wrote:Banding seems to be there when converted to rec709, but I cannot be sure it’s there in raw, but I’m thinking it probably is.


There is certainly no banding in 12bit raw.


I've actually had it happen in camera. Certain textures can create moire that show up in BRAW footage even without a grade on it.

Re: Colour banding in 12 bit braw

PostPosted: Thu Jun 08, 2023 5:29 pm
by Robert Niessner
ShaheedMalik wrote:
Robert Niessner wrote:
ktaylor355 wrote:Banding seems to be there when converted to rec709, but I cannot be sure it’s there in raw, but I’m thinking it probably is.


There is certainly no banding in 12bit raw.


I've actually had it happen in camera. Certain textures can create moire that show up in BRAW footage even without a grade on it.


Yes, but moire isn’t banding.