Originally Posted by DanielT74 
But why exactly is this so (forgive me if I am asking the obvious) too much illumination??
As Ben mentioned, it's because of the angle of the light. It's similar to holding a flashlight to illuminate someone's face - if you stand in front of them and point the flashlight directly at them, the lighting will be relatively flat. But if you give the flashlight to the person and have them hold it below their face pointing upward, you'll get dramatic shadows!