Thanks to all for your helpful replies...

tonixus

The  Atmosphere Global Lightning Adjustment for Dark and Bright fixed the problem. Thanks.. I was thinking that the adjustment had to happen in the Light Editor instead of the atmosphere.  The light shadow softening  adjustment was good tip also.

bruno021 

The "Glow" parameter  was already low the "scattering anisotropy" was high. So

changing them did not change much. The problem seemed to be that the Global

light and adjustment was way out of kilter. I 'll play around with these anyway.

Thanks 

           gtrdon