Frame Buffer to any file format....

[aaronrumple]

I'm not getting the same image from the vray frame buffer to an exported file of any sort. You'll see the comparison of the frame buffer to the image opened in Photoshop - the image is losing contrast and richness. I suspect the new settings of "Color Mapping Only (No gamma)" combined with the sRGB curve of the vray Frame buffer are the culprit.

 

In 2.0 I used Color Mapping and Gamma and left the sRGB curve un-selected. Then applied an inverse gamma in Photoshop. Things were pretty well spot on from frame buffer to final image then. Now I find myself having to apply additional curves and correction to final images to get what I had in the frame buffer.

Edited June 16, 2015 by aaronrumple

[aaronrumple]

Here's a side-by-side with "Color Mapping and Gamma" burned in. A much closer match from frame buffer to exr in Photoshop.

[Chris MacDonald]

I've always thought the VRay frame buffer gamma curve for sRGB colour space was a bit different to what my images were saving out as; but then I noticed I was working in photoshop in Adobe RGB.

[Stephen Thomas]

The sRGB button has no bearing on the saved file, it just flips between viewing in linear and sRGB colour spaces. Whichever format you save to though, when you open in photoshop you will be viewing in a gamma-corrected colour space (usually sRGB). Either by saving to jpeg with 2.2 gamma, or by saving to a linear format like exr or hdr and viewing a gamma-corrected preview.

 

Trying to save the linear version out as a jpeg by applying some gamma trickery, while you may prefer the look of it, isn't really technically correct. What you should be doing is adjusting your textures and lighting to achieve the contrast you desire while viewing in the correct colour space (sRGB button on). For colour swatches you can use the VRay colour map, and for textures make sure your import gamma is set to 2.2.

[Stephen Thomas]

Here's a side-by-side with "Color Mapping and Gamma" burned in. A much closer match from frame buffer to exr in Photoshop.

 

If you're burning in gamma during rendering, then leave the sRGB button off and save to jpeg at gamma 1.0. There is apparently a small difference between the gamma curve applied by 3dsmax in the frame buffer and the sRGB curve applied when saving the file, as noted in this tutorial: http://www.aversis.be/tutorials/vray/vray-20-gamma-linear-workflow_01.htm

[aaronrumple]

Yes, yes, burned in gamma ad sRGB off were my standard settings in 2.0 with exr out @ 1 linear workflow and all.

 

I guess I never noticed the big difference between VRay's and PS's sRGB curve until trying the 3.0 defaults of not burning in the gamma. You'll see in the first screenshot, the sRGB preview in the frame buffer is considerably different than the same file in opened in PS. With the gamma burned in and sRGB off, the preview closely matches PS. Since I don't like to do too much post production - it is more important that the frame buffer very closely matches the end result in PS. Without burning in the gamma - it is too far off.