Are channels supposed to have a curve applied to them?

[ValeroStudio]

Whenever I save out my channels for working with in post, I always feel like they are too bright. I was taking a class on Udemy about post production and he includes his channels saved out from Max is a working file. I noticed something. I noticed that Max doesn't seem to be applying the RGB curve on the channels when saving them out. They seem to composite cleaner.

So I did a test. Rendered a teapot with reflection and saved out a reflection channel as normally and then saved one out with the Display Colors is RGB Space turned off. The latter seems to composite correctly. Should V-Ray be applying the curve correction to the channels?

If I save out my GI, Lighting, Reflection, Specular, etc and stack them in PS and set them to Linear Dodge, the result is a very blown out rendering. So this leads me to believe that something is not correct.

[vlado]

What file format are you using to save out the render elements? I think only OpenEXR will work correctly out of the box; any other file format would require you to first remove the sRGB curve, then do any compositing operations, and then reapply the sRGB.

Best regards,
Vlado

[ValeroStudio]

What file format are you using to save out the render elements? I think only OpenEXR will work correctly out of the box; any other file format would require you to first remove the sRGB curve, then do any compositing operations, and then reapply the sRGB.

Best regards,
Vlado

I just tested saving out an EXR and it seems to be producing the same result. If I save out a multilayer EXR or just the channel in EXR, this is how it looks. Seems incorrect, no?

[konstantin_chaos]

Hi Matthew,

Can you please share the output images (the EXRs) that you've used for compositing?
Additionally, can you describe the step-by step process of rendering and putting them together?

As Vlado mentioned, the best option for you is to save out EXR channels.
V-Ray will automatically make sure they are linear (no sRGB curve baked).

Once you start loading them in PS make sure to import the alpha as 'channel' (and not transparency) to avoid issues further down the line.
Keep in mind that the image will be loaded in 32bit mode.
It'll appear as if the sRGB curve is applied.
This is actually just a display thing. PS will use the linear/raw colors for compositing.

You also might want to check your Photoshop Edit / Color Settings...
Make sure that your Working Spaces / RGB parameter is set to 'sRGB ...'
This way the end result should match what you see in the VFB.

I'll be able to give you more info once I have the files.

Regards,
Konstantin