Blackmagic Forum

I have been noticing that sometimes the image in the viewer doesn't match the image shown on the clean feed in my other monitor, even when both are set to display the same node. Obviously there are differences between my monitors, but the differences also show up in screenshots, so it's not because of the monitors. Here's an example:

Is Resolve set to colour managed mode?

There's an issue with the Clean Feed viewer where it either does or does not automatically apply a LUT - I can't remember which. And unlike a normal viewer, there's no buttons visible to change the viewer LUT. But I think you can move your mouse pointer over the clean feed and right-click to access the LUT menu.

I can't remember all the details, but almost certain it's to do with viewer LUTs.

I'm not using Color Management, no. I'm also not seeing a menu when I right click the clean feed. I am still on 17.2.2 though; is that a newer feature than that?

EDIT: I think that the only footage I've seen that happen to is some BRAW I recently added to my project, which has so far only been h.264.

Right yes, I've recreated it. And I think it's the opposite of what I said - there's an issue if you're not in Davinci managed colour.

For me, on macOS, if I right-click on the Clean Feed monitor I see the right-click menu appear on my main monitor. In that menu I can then go LUT -> untick Enable



And then the Clean Feed viewer looks fine.

I think what's happening is that the Clean Feed assumes you are in DaVinci Color Managed, and enables the "Managed" LUT. So if you're not, you need to disable that viewer LUT - or enable the appropriate one, eg an sRGB/rec709 one if you're comping in linear.

Hah! That appears to be a very large list of settings I have no way to access... Any chance there's somewhere else to find them? Project Settings > Color Management > Lookup Tables seems like a good place for something like "Video clean feed LUT" or whatever, but there are still quite a few others. Is there even a way for a typical user to find out that those settings exist aside from reading the manual, right clicking on the clean feed for no particular reason, or being informed by their favorite more knowledgeable bloke on a web forum?

Ok ok, I was wrong. It works on the Fusion page only. I forgot that you can't always do the same thing the same way on every page. But I can still only do it at all on the Fusion page. Is there a right click drop down of viewer settings for the clean feed in the edit and color pages that I still can't see though?

That's the Fusion context menu, only available in Fusion. There's no viewer context menus in other pages.

Do you need to change viewer settings on other pages? I thought the clean-feed-looking-different issue only affected Fusion.

I don't think I need to change anything anywhere else, I was just trying to make sure there weren't settings I didn't know about and/or wasn't able to access. But that begs a series of follow up questions: Why does the clean feed in Fusion need a LUT? If a viewer doesn't match because it's not using a LUT, doesn't that mean its input is being changed before it's being output (something I would assume a viewer shouldn't do unless I told it to)? And if the Fusion page is missing a LUT application on its clean feed, does that mean there's a LUT being used on the viewer everywhere else that I didn't know about?

Most importantly, if there's a LUT conversion happening that I didn't know about, where is it happening in the signal flow of the deliver page's export process?

TCP786 wrote: Why does the clean feed in Fusion need a LUT?

It doesn't, necessarily. I don't know why it always applies the Managed LUT - almost certainly a bug/mistake.

That said, it is normal and recommended practice to comp in linear, so in practice you'd likely always want a Rec709 or sRGB LUT on all viewers. Even so, the Clean Feed being in the Managed LUT is still a bug I think, because I'm pretty sure that only functions correctly when Resolve is in Color Managed mode.

TCP786 wrote:If a viewer doesn't match because it's not using a LUT, doesn't that mean its input is being changed before it's being output (something I would assume a viewer shouldn't do unless I told it to)?

The Clean Feed viewer didn't match because it WAS using a LUT, when it shouldn't have been. You had the Managed LUT on the Clean Feed, and (I assume) no LUT on the other viewers

TCP786 wrote:And if the Fusion page is missing a LUT application on its clean feed,

What do you mean, missing? The LUT feature is available and working on the Clean Feed - you change it using the method I described earlier. The issue was that it was seemingly turning on the Managed LUT always, even when you weren't in DaVinci Color Managed mode (which is when the Managed LUT is used)

TCP786 wrote:does that mean there's a LUT being used on the viewer everywhere else that I didn't know about?

In Resolve, if you enable Davinci Color Managed mode, then the viewers will default to the Managed LUT. Otherwise Fusion viewers default to no LUT (except the Clean Feed, which appears to apply it regardless), and if you want one you need to turn it on using the LUT button in the top right, or via the right-click context menu. You can then save that as a default for the viewers, if desired.

TCP786 wrote:Most importantly, if there's a LUT conversion happening that I didn't know about, where is it happening in the signal flow of the deliver page's export process?

Nothing. Viewer LUTs are just for viewers. If you want a LUT or colour space conversion in the deliver pipeline, you'd add a LUT or Gamut node. As mentioned you are likely to want a Gamut node for removing the gamma curve of source material (making it linear) prior to comping, then another Gamut node to put it back into Rec709/sRGB at the end.

Here's some tutorials that might clear up a few things for you: