Whatever I do the Desaturation node also changes color luminance. I think the desaturation just isn’t working right, at least in a post processing material?
This makes the problem very clear:
The post processing without the desaturation node:
That image desaturated in photoshop:
The post processing with the desaturation node:
As you can see the color luminance of the yellow becomes brighter but it isn’t brighter anywhere.
Now i know the desaturation does it somehow at a different position in the post processing chain but even when I turn off the tonemapper with setting it to Replacing The Tonemapper in the material the issue remains. I also tried changing the color luminance factors in the desaturation node to grey but that didn’t help either.
It this a bug and is there any alternative to the desaturation node in a post processing material?