I have been wondering a lot about this, hope somebody can help me out.
I use the colors curve correction on the Vray Frame Buffer quite a lot during Rendering, but I usually save my Buffer Output without the curve correction and then re-correct these in 8-bit Post. (PS)
My question is:
are the Curves Correction in Vray FB appplied on the HDR level of the image? or just the visible range?
in other words, do I achive the same effect when saving in 8-bits and then applying the same/similar curve in Photoshop? or am I losing color information by doing this?
VBR is 32 bit if I’m not wrong so if u apply the same curve in PS on 8 bit image they will differ. I think you need to apply that curve in PS on 32 bit file… Unless I mist something
Hi DADAL, i also would tend to think the way you do, but I did some practical tests today which seem to demonstrate otherwise, (similar results on VFB and 8bit post) would be interesting to hear others opinions, one thing I have noticed is that the VFB curves correction Panel allows one to place vertex/points outside the 0-1 range and the curve itself can also be placed outside of this range, while Photoshop doesnt allow this. but I still cant seem to get more information on my pictures by using the VFB curve than by using Adjustment curves in 8bit Post…
Humh interesting I think I watched some feature video from chaos not so long ago where one of chaos presenters was talking about VBR and how its 32 bit + show us some examples of exposure. Which were not possible if it was 8 bit. Strange. Can you try maybe Nuke? I think Nuke is A LOT better at color managment than photoshop. PS got a lot of mathematical bugs
The V-Ray VFB can save the curves in PhotoShop .acv format; there a slight difference in the resulting curves (we use Bezier curves wheres PhotoShop uses splines), but on the whole it should be quite similar within the 0-1 range.
