Emissive materials are black instead of white in the diffuse light render pas

It’s annoying that emissive materials are black instead of white in the diffuse light render pass because you can’t distinguish emissive from shadows then:

Also, the diffuse color pass correctly shows the mix shader gradient, but the diffuse light does not.

If it was an alpha value so you could mask out the emissives, I’d get it, but I don’t think they are?

Just for comparison, here’s the final and emissive passes:

Yes, yes, I get that you can use the emissive render pass to mask it, but it’s just an extra step… a paper cut.

A screen of the nodetree might help us understanding why you get those passes. Also I didn’t understand, what is that up-right image?

Upper right image is the diffuse light pass (2.9).

Cylinders from the first picture: you have the diffuse color, which goes from red to null driven by a gradient. Looks correct to me, just like in your Mix shader node.
In the 2nd image, the black circle on top of the cylinders also looks correct, since that part of the geometry isn’t affected by light (emission shader doesn’t receive light, unless you use it mixing or adding to a diffuse). The only doubt I have is if the gradient should appear here too.
A question: why diffuse pass has lens distortion filter?

That’s a good question for the Blender developers. :slight_smile:

The highlighted add shader node might help you in getting better passes

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Answering myself: there is no vertical (z) gradient in the 2nd image (directdiffuselight pass), so it’s correct.
But, the correct original question was: in the 4th image (emissive pass) shouldn’t it go from bright red to black?
Again the image is correct: the gradient starts from black (a thin layer of black at the very bottom) and immediately gets red as the gradient goes > 0, since the red emission strength is quite high. (i.e 0.010 in the gradient translates as 0.63 red emission)