Uncheck the Automask control. It is causing the spots where the tones are close enough to match.
Thanks for this, although it's a super-disappointing answer. Oh well. Again: thanks.
I never use the Brush in AutoMask mode. I do use the Eraser extensively in Automask mode. A reverse-mindset on this might give you just what you are looking for.
Why? Because it's a function, and AutoMask has been very helpful to me. I'm finding that it almost seems to function well when turned off now.
As to the eraser, I will have to check it out, and thanks! Of oourse erasing is the last thing on my mind in this case.
@Adobe: this is all getting very Lewis Carroll, y'know?
Thanks again, Rick...