Color Management

[DCHA34]

Hi,
I would like to know more about Color Management.
Let me explain:
I have to reproduce interior ambiences with very specific colors. These colors are provided by the customer in CMYK.
The client wants the 3D rendering to reflect "exactly" (humm... I know it's impossible) the color samples provided.

So I'm thinking of converting the CMYK values into RGB with Photoshop.

Now I wonder how to enter these RGB values from Photoshop into V-Ray.
Should I enter them in RGB or sRGB in V-Ray so that the rendering is consistent with the CMYK sample.

Last thing, do you have a configuration file for a totally neutral lighting, a lighting that allows to keep the maximum correspondence with the original color?

I know I'll still have to do some post-production color correction, but I'd like to get the closest raw rendering possible.

Thank you very much.

[slavcho.brusev]

Hi,

I think the fastest way to move colors from Photoshop to V-ray Material is to batch export textures(I know they will be plain color) and load them in the diffuse slot in the material. Entering manually the RGB values will take forever.

do you have a configuration file for a totally neutral lighting

No, but my suggestion would be to use only white(grayscale) lights. This means that if you are using the Sky texture in the Environment slot, you will have to replace it with a black and white one(or collor correct it). This is because the Sky will give mostly a blue tint so we need to avoid this.
Additionally the pure diffuse colors are stored in the Duffure render element(https://docs.chaos.com/display/VSKET...ender+Elements), this might help in post.

[konstantin_chaos]

Hi DCHA34,

So I'm thinking of converting the CMYK values into RGB with Photoshop.

You will certainly have to do this.

Now I wonder how to enter these RGB values from Photoshop into V-Ray.
Should I enter them in RGB or sRGB in V-Ray so that the rendering is consistent with the CMYK sample.

You should use the Screen (sRGB) color picker mode to specify the color values.
The Rendering (RGB) mode is what V-Ray uses internally for raytracing and if you specify the colors there they'll appear washed out in the VFB.

Maybe it makes sense for me to write a more detailed article about how the V-Ray color management functions.
I'm sure you'll feel much more confident once you understand how everything works.

Konstantin

[DCHA34]

Hi DCHA34,


You will certainly have to do this.


You should use the Screen (sRGB) color picker mode to specify the color values.
The Rendering (RGB) mode is what V-Ray uses internally for raytracing and if you specify the colors there they'll appear washed out in the VFB.

Maybe it makes sense for me to write a more detailed article about how the V-Ray color management functions.
I'm sure you'll feel much more confident once you understand how everything works.

Konstantin

This is a great idea !

Another question comes to mind:
In Photoshop should I assign my images the sRGB color profile, the Adobe RGB color profile or should I leave it without Color Management ?