I’m not sure if this was going on in vray 3.2, but in 3.3, I’ve noticed that if you have bloom and glare turned on, and set to ‘render element only’ the rgb color pass darkens by 2.5-5 stops. if you turn them both off, the image brightens again, and similarly, if you set them to ‘image only’ or ‘image and render element’ it brightens back up.
im attaching screen grabs of the vfb of the first scene where i noticed it (originally created in 3.2, scene darkened by about 2.5 stops). ive tested and recreated the problem in a fresh, simple scene with a cyclo, a teapot, a vraysun, and a vrayphysicalcam (image darkened by about 5 stops). turning them on and off and changing them around a bunch, i think it is the bloom effect that is the culprit. hope this helps.
