I just wrote a 3 page explanation of how this works one some machines and some not and on friends and production house having different experience. Then I clicked Submit it and I was logged out and the post is lost...
So here is the short version.
Was on 15.3 Lite on my main computer long time ago, having this setup for Grain:
This is made in Clip Panel so to add this to entire Video
Add 2x Layer Nodes (2x ALT+L)
Remove Feed from source to lower Node
Add Film Grain Matte to Lower Node
Add Alpha Channel from Matte to Lower Node.
Set Composite Mode to
Linear LightSet Key to about 0.300 (to your taste)
This used to yield exceptional results, with a very natural grain that merged with the Highlights and the Shadows.
I upgraded to 15.3 Studio and now exact same setup gives extreme Gamma shift. No matter what Composite mode, there is always either a slight or heavy gamma shift.
So I revert back to 15.3 Lite. The Gamma Shift stays, the Layer Mixer is broken.
Also when Disabling all nodes
(ALT+D) in this setup after upgrading to Studio the image goes black, this did not use to be prior to the broken Layer Mixer.
Same for Version Studio 16+.
Been abroad for 3 Weeks.
I brought my crappy Laptop that has been running version 15.3
LITE. Strangely enough on this Laptop the
Linear Light Composite Mode never worked, it Gamma Shifted like the Studio version does. I have been messing about with some grades and what not, playing around with Cinegrain and I stumbled upon a Workaround.
Workaround:
Add 2x Layer Nodes (2x ALT+L)
Remove Feed from source to lower Node
Add Film Grain Matte to Lower Node
Add Alpha Channel from Matte to Lower Node.
Switch the Feed from the two Nodes to the Layer Mixer, so Lower Node goes in Higher Input and Vice Versa.
Set Composite Mode to
MultiplyAnd Voila! You get the beautiful grain with no Gamma Shift, merged beautifully with Highlights and Shadows. Also Disabling all Nodes now does
not make the screen black
(ALT+D). Only Caveat was that you could not Key out the grain this way, but I have full collection of Cinegrain so I have been able to find a suitable stock everytime.
Happy Happy days, so today I upgrade Resolve on this Laptop to Studio 16.12 and now this Workaround
does not work anymore, instead it clips highlights like crazy. Disabling Nodes does not make the screen black though.
I feel these issue are very random at best, like some code being changed in one part messing up another? What is being changed under the hood causing this?
Edit: So this was the short version and I forgot to add that the issue is that the
LAYER MIXER is obviously broken.
EDIT II: I just noticed now that this is in the BETA section, I am not running Beta but the issue is still there.
See also: L*a*b Color space issue:
viewtopic.php?f=21&t=88475&p=548029&hilit=LAB+color+space#p548029