polarizers

[AlanKlein]

Right now in my neck of the woods about 1/4th of the sky is scattered with extremely thin cirrus clouds. Want the height of the clouds?? Aproximately 30,000 ft. Or in my terms: SCT300. The part that is not covered is a weak shade of blue. I would love to take a pic of those clouds but it all blends together and there is no definition. A polarizer would give me that definition BUT apparently I can't do that because I don't want to include the fricking trees.

Use a polarizer that would darken the sky and a split neutral density filter that would block the trees somewhat but allow all the light from the polarized sky to pass through the lens. Coken filter systems might help do this most easily.