Try moving the sun more down towards the bottom instead of up on top. I find about half to 3/4the of the way down is good and depending if you want it shining from the left or right  you would move it right or left. You can do it in the sky lab too and click the little down arrow below the render and click on render in scene it will show you how it affects the scene as you move it.

Sandy
An imagination can create wonderful things

SndCastie's Little Haven