Dear Alert Future Reader:
Black Bottom Disease is like my wife's cousin's sheep get in Sibford Ferris, but this solution beats digging maggots out with a trowel. I won't say where from.
It's not my idea but I will bask in the glory of writing the solution - to place a second sun in the scene that casts no shadows with a manual sun angle - altitude set to -90.
Setting changes include: adding yellow to the original sun - power 40 - light sources 10 divergence .5 degrees
Sky light bluish 25
underground invisible sun also bluish.
adjusted exposure and saturation in photoshop
I get the feeling that the Police were writing about LightWorks when they did that "invisible sun" song.
Dwight Atkinson