@johnt and I were discussing the strange occurrences of super-saturated, clipped color that can appear in media these days, and I’m starting a thread here to have constructive conversation about it. I’m gonna see if the mods (firing up the @randy signal!) can move our bits of thread into this one.
Hi. Has anyone noticed weird chroma on streaming movies? On Apple TV, Amazon and Netflix there’s been a lot of what looks like pools of negative blue at certain points. I thought it was the tv but I’m. Im so sure now. Thought I’d mention it given these post.
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I think this is a side effect of pushing the saturation too hard way out on the gamut frontier. I’ve caused it to happen in my own work, and it is, as you say, one of the colors going negative and just spiking the living hell out of the others.
I know when I was experiencing it, the problem was if i clamped the colors, they’d fill with white, or desaturate way too much. I have a note somewhere in my phone to “look into saturation soft clipping” but that note is at least a year old.
Thanks for reminding me John.
Latest one I noticed this on is “Sorry to bother you” on Netflix. It’s all over “The morning show” on Apple TV. They do look ok on the iPad though. When I first noticed it I was going to call up TeaTray at Company 3 and crow. But then I started to doubt: wondering if it was our TV.
I will check it out any specific timecode/episode where you see this?
In my testing appleTVOS and iOS would show the same pixels on a stream (I captured the HDMI output from the appleTV and did a screen recording on iOS) both seem to be unmanaged for SDR content , at least for files, plex, youtube, vimeo and frame.io… thumbnails are Color managed by colorsync as are still images but not video content… its such a mess…
So my setup is a Mac mini into the tv. I had a thought and changed the profile on the Mac to aces. It has improved the problem. It’s still there interested to hear what you think.
As you wish…headed into a session, lemme know how I did and I’ll revisit this this eve…
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I will check that out, are you using the netflix app for macOS or a webbrowser?
Ha, sorry I cant , its not available in German Netflix 
We’ll use this thread to compile instances. It’s not just that movie–I’ve seen it in various things. I’m in the middle of moving house so I’m TV and Netflix-less (for the most part) for another few weeks.
I feel like every nightclub scene in every movie has this issue. Haha.
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Thank you Randy.
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It’s all over the morning show on Apple TV. As I say I nearly called company 3 up to call them a bunch of amateurs in my best stone roses impression.
Still it’s a worry. You slog your guts out on a show and then you see your work 
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I don’t have a specific example to contribute but I do have some information about this subject! It’s certainly a known phenomenon and I think a lot of what has been discussed is exactly right- negative / clipped values as a result of out of gamut color. Neon lights are the big offender, and I believe it has to be with how the color management is reading the raw data.
When I was exploring the world of color grading in Flame this subject came up, and my Baselight colleagues mentioned a tool of theirs called “Compress Gamut”. Here’s a little blurb on the subject from Baselight:
Compress Gamut
The new Compress Gamut operator fixes strange colour effects in
saturated colours from very small or negative RGB values. Turn up
the threshold to see the effect. 0.1 is a typical threshold setting.Suppose you point a camera at a scene with a bright yellow light.
The camera records sensible raw red and green signals from the
yellow light, but the raw blue may be little more than noise. When
the raw signals are converted to image RGB, the blue channel may be
very noisy, clipped, or negative. Subsequent grades may make this
worse.In this yellow light case, Compress Gamut picks up when the B value
is much less than max(R,G), and applies a smooth function to map all
small and negative values onto small positive values.
Shameless self promotion for my feature request about this subject here.
interesting, shouldnt netflix QC catch the Out of gamut stuff if there is any?
So the master files delivered to netflix etc , I guess are 0-1 range(jpeg2000?) so dont contain any negative or out of gamut values.(minus this rgb->ycbcr stuff shouldnt be a concern for netflix) So this can only happen when someone clips the gamut at some point?
Or it could be someting with HDR masters and their SDR trimm, just guessing here havent done netflix mastering , just vfx work.
Also for the grading part, gamut compression is nice and is usually part of any well made “ODT” or “DRT”, so aces for example give you that “for free”, thats also what all the wide-gamut to 709 Luts will do .
But there still are some issues with neons as you said, as you end up with negative values when ingesting the raw plates into aces, when the colors are out of gamut, its fun. but should in any case really be caught by either grading or finishing. No auto-tools will find this stuff if it has been clipped off allready.
Hi the compress gamut is something I was trying to get hold of to use in flame. Had a right to do with an advert. Discovered the problem eventually. The shot was graded and all legal. It was reracked and this made the chroma spike out of control outside the vector scope. I tried tho build my own compressor in flame but didn’t quite get it to work. It would certainly be a very useful tool to have. I got too busy to investigate the compressor further.
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I too have noticed this and also thought it was my TV, however, I can’t say I’ve noticed it when watching on my iPad.
Perhaps it is our TVs. Perhaps Rec709 is dead.
I’m still diggin through this thread but had to stop here for a moment. I’ve see a few of things come out of Co 3, especially in longer format, that have this quality. I wonder if it’s something on their end?
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