I've just developed 4 rolls of FP4, all taken from the same pack of 10. The films were developed in pairs in Jobo 1500 tanks/reels. I'm bewildered to find that in each case, one film shows strong edge markings and the other shows very weak markings. We're talking big differences. The developer was Perceptol 1 + 3. Neg density is inconclusive as I was running tests. Markings are consistent on each side of the films. Markings are consistent along each film - implies there is no inner/outer difference. Films all came from 1 pk of 10 but I discarded packaging so can't check batches.(posted 8570 days ago)Any suggestions?