Luma Mix

In DR16 when I changed "luma mix" to 0 I could adjust red, green, blue independently of each other (if I adjust blue, red and green would stay the same). Now when I try this in beta it doesn't have the same affect. Is this a bug? If not how can I achieve the same result in 17?

Oooo, I think I've seen this and it puzzled me for a second and then I just shrugged my shoulders and ignored it. Multiple things moving in the Parade and my Mix was 0. This was in 17b5 and maybe 17b4, but not sure.

I hadn't tried until 17b4, updated hoping that was it but no luck. Would be a bummer to lose that ability I really liked it.

I checked this with 17b5 and it worked properly. Setting luma mix to zero and then drag up and down the individual color bars only impacted that specific color on the parade.

I checked this with 17b5 and it worked properly. Setting luma mix to zero and then drag up and down the individual color bars only impacted that specific color on the parade.

If I reset the node and go to Primary Bars (or drag a single color below Primary Wheels) whether the Luma Mix is at 0 or 100, I get basically the same results. Move one color, moves the others in the Parade. Once I've moved one like this I can sweep Luma Mix from 0 to 100 and back and all it does is raise and lower all three colors in the Parade in unison.

Am I misremembering how this is supposed to work, or are there any other setting/preference that would cause this behavior? The manual says:

Lum Mix: Lets you control the balance between YRGB contrast adjustments you’ve made using the Master Wheels or ganged Custom curves, and Y-only adjustments to contrast made using the Y channel Lift/Gamma/Gain controls of the Primaries palette or the unganged Luma curve. At the default of 100, YRGB and Y-only adjustments to contrast contribute equally. Reducing this value diminishes the effect of Y-only contrast adjustments until, at 0, Y-only contrast adjustments are turned off.

Additionally, you’ll notice that at the default Lum Mix setting of 100, individual adjustments to R, G, or B using the RGB sliders or unganged Custom curves result in automatic adjustments being made to the other two color channels in order to maintain constant Luma levels. At a Lum Mix setting of 0, individual color channel adjustments have no effect on the other color channels.

Am I misremembering how this is supposed to work, or are there any other setting/preference that would cause this behavior?

If you do this before some other adjustment, whether it be a colour/contrast adjustment in a node or LUT, or just doing something in a colour managed mode, then the adjustment you make in one node will affect how the image is processed later on, so yes, other colour channels will move even with Lum Mix set to 0. If you do this as the last node in a DaVinci YRGB project though, then individual colour channel adjustments will only affect that channel.

... or just doing something in a colour managed mode, then the adjustment you make in one node will affect how the image is processed later on ... in a DaVinci YRGB project though, then individual colour channel adjustments will only affect that channel.

Genius! I have only one project that is color-managed -- as an experiments -- and that was the one I opened to test it. Opening a DaVinci YRGB project (my normal use case) and it works as remembered.

I was also suspect of RCM as there have been other bugs related to it, so I had tried both and it worked.

I just tried it again just to make sure. If I only have one node or it is the last node in the chain, luma mix set to 0 works as expected. Moving say the color bar slider for the green in the highlights just impacts the green channel in the parade.
And as Tom mentioned, if the node is before other adjustment nodes, setting luma mix to 0 and then adjusting the slider shows other channels moving as well. You can switch to highlight mode to kind of solo that one node and luma mix and the slider only impact the one channel.

I also tried with unganged custom curves and that also worked as expected.

This is with b5 on Win10...

I was also suspect of RCM as there have been other bugs related to it

this isn't a bug

Hey all,

Thanks for the responses! I really appreciate it.

When I put lum mix to 0 on the last node it performs as I hoped (if I work on blue only blue changes)

However, I also noticed something that I think will help others if they aren't already aware of it. If the first thing you do is change lum mix to 0 (as in there is only one node at the time) you can then add nodes no problem and the first node will perform the same. This allows you to color balance on the first node before doing anything else.

I also noticed something that I think will help others if they aren't already aware of it. If the first thing you do is change lum mix to 0 (as in there is only one node at the time) you can then add nodes no problem and the first node will perform the same. This allows you to color balance on the first node before doing anything else.

There's also an option/preference to "Set Luma Mix to 0 when starting new projects" somewhere. This may be helpful in case we forget to adjust it when we start. (As I always do)

EDIT: It's "Luminance Mixer Defaults To Zero" and it's in the General Options tab of the Project Settings.. So you have to set it for each project I suppose(?). I would prefer it to be a global option rather than having to remember to set it by the project..

I always keep an empty project with my favorite settings.
When you start a new one, there is the function "Load Project Settings to Current Project".

I also noticed something that I think will help others if they aren't already aware of it. If the first thing you do is change lum mix to 0 (as in there is only one node at the time) you can then add nodes no problem and the first node will perform the same. This allows you to color balance on the first node before doing anything else.

There's also an option/preference to "Set Luma Mix to 0 when starting new projects" somewhere. This may be helpful in case we forget to adjust it when we start. (As I always do)

EDIT: It's "Luminance Mixer Defaults To Zero" and it's in the General Options tab of the Project Settings.. So you have to set it for each project I suppose(?). I would prefer it to be a global option rather than having to remember to set it by the project..

uh HELL YES, would be nice if there was a global option but i'll take project wide! thanks a ton

I always keep an empty project with my favorite settings.
When you start a new one, there is the function "Load Project Settings to Current Project".

clever! i'll be trying this for sure

I always keep an empty project with my favorite settings.
When you start a new one, there is the function "Load Project Settings to Current Project".

clever! i'll be trying this for sure

Yes, I keep planning to do this too. Thank you for the reminder