Ok been doing some experimenting.  Followed your advice and seems that certainly PTA ‘magnifies’ the issue.  Without PTA or ENVTEX I don’t see the problem so much on the cowling or combing but still see it down on the ground.

Also noticed that the problem occurs when the view direction approaches and hits 90 degrees from the direction of the sun.  I.e. if I am flying with the sun bearing 270 from me and I turn from the sun and look dead ahead to my 12 o clock, I lose the shadows from the clouds and the sunlight effect on the combing.

Maybe this is just one of those things.  Noticing it more in this scenario at Yellowknife in Winter with fair weather and a sunrise.  Maybe this is just the perfect environmental combo to make this problem stand out more.

Thanks for your help by the way!

17 hours ago, Robkr1208 said:

Followed your advice and seems that certainly PTA ‘magnifies’ the issue.

Which is logical because most PTA presets deepen the shadows. But things like this happen all the time, even without PTA.