Creating Believable Materials - Photographic Rendering with V-Ray for SketchUp - page 196

Enabling the Don't affect colors control means that while our light
bounces in the scene will be calculated in a properly gamma-corrected
color space, the colors seen in the render itself will remain linearized.
This, for me at least, gives a best of both worlds approach as the lighting
illuminates the environment in a much more natural way, while the colors
on the materials are rendered much more in line with the values chosen
inside the material editor.
As we ideally still need to be able to see our renders in a final gamma-corrected
form, we have to perform the following steps:
1. On the V-Ray toolbar, click on the F icon for the Frame buffer.
2. In the controls found along the bottom of the V-Ray frame buffer window,
click to enable the sRGB option.
3. We also want to open up the Camera rollout and dial back our exposure a
little by setting the F-number to 8 , the Shutter speed to 150 , and the Film
speed (ISO) to 200 .
Note
With the Srgb button enabled, the V-Ray frame buffer is now giving us
a pretty accurate representation of what our render will look like with a
2.2 gamma correction applied to it. I say pretty accurate because despite
advice to the contrary sometimes be found on Internet forums, an sRGB
color curve is not actually identical to a gamma 2.2 correction (although it
is very close in terms of the final look).
Do be aware that this correction is only seen in the V-Ray frame buffer
itself. If we save an image to disc either by means of the frame buffer win-
dow or through V-Ray's output controls, we get (as seen in our render)
a linear, non-corrected image that is ideal for working with in a post-pro-
duction application.