Missing bt709 tags rendering "limited" from ACES 32 bit full

Mindmatter wrote on 9/26/2025, 2:00 PM

I just uploaded a studio RGB version as i remembered it was recommended for youtube, but it just doesn't look quite right. The blacks and general contrast and saturation don't look as they should compared to my full range version here on my PC..
EDIT: I just uploaded a full range version to test, but that doesn't look right either. Some scenes ( not all ) are oversaturated and the blacks aren't totally crushed but way too contrasted.The DJI drone footage also becomes too contrasted.

So what's the solution and current consensus for YT?

Thanks!
EDIT: I just saw that all the XAVCI 422 clips from my FX3 as well as the DJI footage reads as "undefined" in the color range proporties. Could that be the problem?

Comments

Mindmatter wrote on 9/26/2025, 3:39 PM

so how do I set the render to "Rec709/limitedRange"? The only option I know of to limit the range level to 16-235 is the studio level filter. I just read that YT misinterprets footage if there is no BT709 tag. I can't see any such tag in Media Info my Vegas renders, and I just read I need to use ffmpeg to actually add that tag.
Is that so?

Mindmatter wrote on 9/26/2025, 5:34 PM

I don't think that is entirely true.There is nothing confusing about it, and the undefined color space is an issue you can research on this forum.
I just solved the problem after some in depth research by actually using ffmpeg to add the right 709 tag to the Vegas render. Not being that tech savvy, it took me quite some work and help of Grok AI.
Fact is, the new tag in the new upload now finally gets Youtube to display my video correctly.
Media Info fails to show the right tags, I had to use ffmpeg command prompts again to see the missing meta data.
Now, as far as Vegas goes, this seems to be a real problem. It should add those tags right away to avoid YT interpretation conflicts. I'm surprised this has never been adressed.
These are missing and also not dhown in Media Info:

colorspace=bt709

primaries=bt709

transfer=bt709

range=tv
And btw, I definitely had to render with studio levels, coming out of a 10bit 422 32 full range project with ACES on.

RogerS wrote on 9/26/2025, 7:37 PM

Yes you render to studio/video/limited range for YouTube still.

Howard-Vigorita wrote on 9/26/2025, 10:07 PM

@Mindmatter You don't want to upload rgb to YouTube... it should be limited range yuv. Which is the Vegas default. You don't need to set anything. If you want to preview the render outside of Vegas to see what it will look like on YouTube, you need to do a limited to full view transform in the viewer. How you do that is different for different viewers... I know mpc-be and mpc-hc have ways to do it but I'm not sure about vlc.

The YouTube upload might not match your Vegas preview, however, unless the project is set to full range. Because YouTube applies a limited to full range transform to all uploads.

Mindmatter wrote on 9/27/2025, 2:28 AM

Well obviously in this case, Vegas didn‘t apply its default and tagged the render wrong, as there was a significant level issue on YT because it wasn’t expanded to full range.The meta data did read YUV limited though on the first renders, but ffmeg clearly showed the missng 709 tags..

I never had this issue with YT before, but I didn‘t use to work in ACES, so I think Vegas doesn‘t add the 709 tags when rendering from a 32 bit ACES project? Levels used to be correct when rendering from an 8 bit full range without a levels filter.

Unfortunately I saw the problem too late and I cannot change the original upload anymore as the link had been sent to too many people already, but I now uploaded the correct version too.

In case you want to see for yourself and confirm the issue, heres the 2 to compare: first link is the usual render with the missing tags and the wrong levels, second link is the one with correct levels with 709 tags added with ffmpeg.

If I had known what I know now when I wrote the post, I‘d have changed the title mentioning the 32 bit ACES issue.

RogerS wrote on 9/27/2025, 2:57 AM

Can you share a screenshot of the render template and project properties? There are a lot of variables here.

RogerS wrote on 9/27/2025, 2:58 AM

What would you like to change the title to? Moderators can edit posts

Mindmatter wrote on 9/27/2025, 3:35 AM

What would you like to change the title to? Moderators can edit posts

Thanks!
If I understood all of this correctly, it's specific to rendering from a 32bit full range ACES project, as I had never seen the issue when exporting from 8 bit full range projects.
So I think the title should be:
Missing bt709 tags when rendering "limited" from ACES 32 bit video levels
Unless I formulated that wrong, but that's my conclusion from this whole thing.

Can you share a screenshot of the render template and project properties? There are a lot of variables here.

I'm not on my main PC right now, will do asap.

EricLNZ wrote on 9/27/2025, 5:44 AM

So I think the title should be:
Missing bt709 tags when rendering "limited" from ACES 32 bit video levels

@Mindmatter Unfortunately it won't fit as titles are limited to 70 characters. Yours is 73, just over. How would you like it?

Mindmatter wrote on 9/27/2025, 5:48 AM

thanks!
so how about
Missing bt709 tags rendering "limited" from ACES 32 bit full

EricLNZ wrote on 9/27/2025, 5:52 AM

@Mindmatter Title change done.

Mindmatter wrote on 9/27/2025, 7:30 AM

thanks a bunch!

Mindmatter wrote on 9/27/2025, 8:31 AM

Can you share a screenshot of the render template and project properties? There are a lot of variables here.

@RogerS here you go:

Howard-Vigorita wrote on 9/27/2025, 4:21 PM

Well obviously in this case, Vegas didn‘t apply its default and tagged the render wrong, as there was a significant level issue on YT because it wasn’t expanded to full range.

As an fyi, YouTube doesn't care what the metadata says, if anything, about range. It always does a limited to full range transform no matter what. If you were to go into the render template and change the default render to full range, YouTube would faithfully and without fail blow out all the highlights. Been there, done that. It might be strictly an Aces issue, however. Aces projects are always full range but the renders should still be limited range for YouTube.

Mindmatter wrote on 9/27/2025, 4:32 PM

well what happened to my video after I changed the meta data obviously proves you wrong.

Why do you insist on denying what I went to great length to show, explain and prove here??Did you even read my posts or look at the 2 videos? Why do you think ffmpeg even exists?

Fyi: The first version was rendered limited too by applying the levels filter but WAS NOT transformed to full range because of missing tags, my full range render got crushed, as expected ,as a test, and once I added the bt709 tags to my limited render, it finally looked right.