Digital BW, The Print

Intuitively I often want to use the inverse of the image to tonally balance.  Sometimes only part of an image.

I am willing to read and have RealWorldPS, Professional PS, and AdobePSforPhotographers all in version 6.  
Just haven't figured out the best way to do this and wanted to put the question to the group.

To put it another way...if an image had overly burned edges all around, but irregularly - how would you go about reducing the effect by 10-20%?

The other thing I used to know and forgot is how to get a good gradient to burn from one edge of the picture to another.  I've been trying but the gradient is altering the color more than I like ( a particularly neutral balanced sand dune, very sensitive).

Thanks,
Cleavis


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