What I've started doing is going to the light tab, like you said, and putting the ambient light to 100% from sunlight and adjusting all of my materials to 100% diffuse and 0% ambient. The basic theory being killing all ambient lighting (which isn't very natural looking) and using fill lights to illuminate dark areas. Also, you can seperate you're lights into individual layers and by hiding layers and selecting render only visible layers in the render panel, you can render the scene with only one light at a time to see just what it is affecting. Like I said, I've just started doing this, so the jury is still out on it, but it might be worth looking into. Rich