You might also want to look at how much your light source shadows are set for, default is 100% which is too much for most things [you prolly know that anyway :-)] so maybe try turning it down if you haven't already!!

I do a lot of scuba diving and you know sometimes you do get dark shadows like that in water [admittedly not as dark, but you do get it!]    :-))

Injustice will be avenged.
Cofiwch Dryweryn.