Archived posting to the Leica Users Group, 2001/11/20
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]on 20/11/2001 5:29 am, Rei Shinozuka at owner-leica-users@mejac.palo-alto.ca.us wrote: > my xtol(1+3) times with a 1 minute prewet were very long; once i > eliminated the prewet, my times shrank down 30%, and in fact became very > close to those published by anchell and troop. (zone VIII == 1.25 > FB+F) > > my prewetting came from old habit, advocated by picker, perhaps. i don't > use prewet anymore for xtol(1+3). > > - -rei > > >> From: "Don Dory" <dorysrus@mindspring.com> >> >> My times did include a prewet for two minutes is water. I will have to try >> shorter times without the water step. >> I tried to get this pre-wetting of films cleared up when I was living in Rochester, NY. I managed to talk to a Koda-person who explained that pre-wetting was a technique for older films with thick emulsions only. Newer silver technology films with thin emulsions should not be pre-wet as the development time and final quality is dependent upon the silver halide getting developer early in the process not by displacing water from a pre-wet emulsion. I asked if this meant we should pre-wet films like Plus-X to which came a sheepish reply that the Plus-X of today is not the Plus-X of yesterday. I'd possibly pre-wet films like Tri-X, FP4, Pan F, Plus-X and HP5 only to get tank and film up to developing temperature - if that was an issue. (I like to develop, wash and fix at room temperature but that's another story). Otherwise I'd treat them like modern film. I'd never pre-wet Delta or T-Max. - -- David Prakel - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html