[numerobis]

Your top example is not recommended because then the layer weight of the top layer will also influence how strong the emitter is, which is in the bottom layer.

yes... this sounds logical

as i said above, i normally use one layer for emitters. But if additive materials are really the same now - good to know

[AlexP]

as i said above, i normally use one layer for emitters. But if additive materials are really the same now - good to know

Little off topic but I often add ND=1 vacuum bsdf to emitter e.g. to be able to turn off it in multilight and not to leave "black spots". It works really nice with IES too.

[numerobis]

Little off topic but I often add ND=1 vacuum bsdf to emitter e.g. to be able to turn off it in multilight and not to leave "black spots". It works really nice with IES too.

ah, yes. thanks, i totally forgot about that.