When rendering in 3ds Max, the adding operations are done in linear space and then gamma 2.2 is applied to the final output (if you are using the gamma 2.2 workflow, which you should be using).
By default, if you just save your elements and add them in Photoshop, you are adding elements saved with gamma 2.2, which is different than what you do in 3ds Max (linear space).
To fix that, you need to make your elements linear, add them, and only then apply gamma 2.2 (or sRGB gamma, or other correction as you wish, if you don't want your result to be exactly as in 3ds Max).
Method 1:
- Enable the Development/Experimental Stuff rollout and use a string option -
https://support.chaos.com/hc/en-us/articles/4528609584017The string option is: colormap.additionalGamma = -1.2
It subtracts 1.2 from the original 2.2 gamma making it gamma 1.0.
- Save your elements in 16 or 32-bit
- Open in PS, Add, apply gamma 2.2 on top
Method 2 - works only in 3ds Max 2024:
- Go to Rendering > Color Management > set it to "Unmanaged"
- Save your elements in 16 or 32-bit
- Open in PS, Add, apply gamma 2.2 on top
I would also suggest disabling color management in Photoshop. Otherwise, you will most likely see your image with sRGB gamma, which is slightly different than gamma 2.2, so you can see small differences, for example in the darkest areas.
