problems w/ blotchy skies

[Frank Petronio]

Learn how to cut path selections in Photoshop....

[Mr. Doyle]

I have had this very same problem and in my case it was not the processing.
If there is moisture in the air (early morning, late evening) or you are bringing the quickloads from cold to hot (coolbag to desert heat) the quickloads can get damp and leave 'mottled' marks on the image usually most obvious in a cloudless sky. Long exposures increase the effect as the cardboard holder can get damp when pulled out from the back..
I am pretty certain this is the case here as this is something that took me months to discover..

[Andrew O'Neill]

This effect happens when I am using stand development with no agitation cycles at all. Noticeable between high and low exposure areas. Ask the guy who develops your film what developer he uses, how fresh it is, what development method he uses, and how much agitation he gives.

[Andrew O'Neill]

Learn how to cut path selections in Photoshop....

Fix the problem at the development stage first. A lot of people don't own photoshop.