Hi all, after getting relatively nice results on my first try, my second batch of emulsion (just the normal basic emulsion + Na tiosulfate gave very low contrast and lot's of gray were it should not be, including unexposed sections. Don't think the fogging happen at the sensitising phase as i tried the gelatin in a piece of paper and there was some considerable grays in unexposed gel. I did 3 different things this time compared to the 1st time, the AgNO3 was older (but it did not appear darker than the other one I used), it was added slower and I use the Na tiosulfate. My developer is D19, normal concentration for films (and ilford Hypan fixer). any suggestions in how to improve the contrast? Many many thanks!