Originally Posted by Francesco
I use a five minute pre-soak time because it adds to consistency of results when testing various films, especialy with short development times. Rate of develoment depends on induction and transfer of chemicals into and out of the gelatin emulsion, and the rate varies among films. At five minutes they all perform about the same. For any given film a 2-3 minutes pre-soak should be fine.
About the stop bath, when using a diluted acetic acid bath the film only needs to stay in the bath for 10-15 seconds. If using water, change the water 4-5 times over a period of about a minute.