luminance material and lumen

[alemanda]

Hi!
Is there any relation between the strength of the luminance channel and the intensity of the light in terms of lumen?

[Erwin Edel]

Surfaces only have a 'glow' sort of postproduction effect, they do not actually light up a scene, as far as I know.

I tried faking a night scene with surface casting light, doesn't work that way, sadly.

[alemanda]

Sorry ...
probably I made a mistake.
look at the attached picture.
I was referring to the surfaces producing lighting ...
I would need to know the relation between the value 100 (is expressed in percentage) and the lumen ... if any