How do I combine diffuse and glossy passes in Photoshop?

Hi guys,

I’m trying to reproduce the Blender Compositing node setup for
combining glossy and diffuse passes in Photoshop but I can’t quite figure it out.

I can combine “diffuse direct” and "diffuse indirect with “linear dodge” and then
multiply the result with “diffuse color” - everything works as expected and equals
the results from Blender.
I can combine the glossy nodes in the same way and also get the correct results.

Here comes the problem:
When I group both setups (1 group diffuse / 1 group glossy) and try to use “linear
dogde” on one of the groups, I do not
end up with the correct result. I tried switching the order of the groups but the result
always looks way too bright and doesn’t equal the result Blender shows when I add
glossy and diffuse together.

Help is highly appreciated.

UPDATE 01: It seems the blend modes I’m using in Photoshop are wrong, contrary
to my first statement the results of the glossy and diffuse setups differ a little bit from
Blender to Photoshop. Does anyone know what blend modes equal “multiply” and
“add” in photoshop?

UPDATE 02: Ok now I tried like every combination off blend modes available in Photoshop
and still fail to recreate what I have in Blender. What am I doing wrong?

Linear dodge and Multiply are the correct blending modes. The problem is that Photoshop by default operates in gamma corrected space, but compositing must be done in linear space. Set your project mode to 32bits: Image > Mode > 32Bits and also set the RGB blending gamma to 1.0 in Edit > Color Settings… > Advanced Controls > Blend RGB Colors Using Gamma (checkbox and value)

Thank you, worked fine. Very clear instructions.
Case solved.