What is the effect on developing times in general as film is increasingly overexposed and 2nd, as the solution is changed to using a higher concentration of "B'' stock? say 1:1:100 vs 1:1.5:100 vs 1:2:100. I ask as I am trying to figure out what kind of times in Pyrocat to try for a roll of Fuji 1600 shot at 640. (It's my exploratory trip for a using a faster film, and I chose Fuji 1600) Would doubling the water give me a greater window of opportunity? I'd try stand development but read that fast films are not good developed this way.Thoughts?