How to add an ambient light ?

Hello and sorry for that newbie question, but even if I’m learning blender from a long time, I’ve never been able to add a simple ambient lighting.
Of course I tried to change the “ambient color” but with that function the black becomes gray. I tried indirect lighting and environment lighting which are very cool but to much complex (and then slow) for what I want.
To compare to something I know, in DirectX we can choose the ambient color which is the minimum light an object can receive, but contrary to blender ambient color a black surface will still be black.

I don’t find searching for ambient lighting, global lighting… Please tell me there’s that simple thing in blender !


EDIT: adding emitting in each material is a solution…