Hi Could anyone tell me what they think is the most likely cause of the marks in the sky on the attached negative? The negatives were developed with a Jobo, fresh chemicals, pre-wash, washes between bleach/fix and fix/stabalizer, correct temperature and great care not to cross contaminate chemicals. Could it be anything to do with having more than one film on a reel at a time? It only seems to affect 120 and 5x4 - 35mm come out great. Thoughts appreciated!