[turbo2000]

Yes i think too that something about the scale or perspective looks wierd, i have checked it but i seems to be right :s

2 more another questions:
What happens i you have a eg. dark bump or rougness map and brightens it, what changes will there be on the material using the same value?

And how could a roughness map look like on a surface like fx. my windows? (so they don't get too diffuse like mihai also mention)