Object renders with slightly different color when changing its "Alpha contribution" value

[Alex_M]

Please check the 2 screenshots below. One shows the plane rendered with alpha contribution of 1 and for the other I've set it to 0. Shouldn't the color of the plane be the same in both cases? The one with contribution of 0 is brighter. This happens whether I set alpha contribution from the V-Ray object properties window or from a VrayMtlWrapper material. I've attached the scene as well. What's interesting is that it happens only in this scene, but completely new ones seem to be fine. I'm not really sure why.

[hermit.crab]

Thanks for the provided scene. The issue stems from the fact that color correction blending modes (other than Overwrite) are dependent on the Alpha channel, hence objects without alpha are not affected. You can workaround this by using a separate CC for the wrapper objects and mask them with an i.e Cryptomatte mask. Otherwise, I'll talk with the devs if there's a better way to do this in the future.

[Alex_M]

Thanks, Aleksandar. I've actually noticed this in my renderings before where I have a sky for example and the sky didn't get affected when using Value blending mode. I pretty much always use the Value blending mode in the Exposure correction layer, because it doesn't make my colors turn grey when decreasing the Highlight Burn value.