Archived posting to the Leica Users Group, 2005/07/18
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]John, Your experiments prove that switching to a neutral fixer is a good thing. The typical acidic rapid fix will in fact serve as a very mild bleach. Don don.dory@gmail.com On 7/18/05, John Black <jblack@ambio.net> wrote: > > > > Feli, > > You will lose the delicate almost unexposed parts of the film, or the > > near whites if it is a print. Without comparison you will never know > > that they are gone. Best to fix by time, you know the twice the time > > it takes to clear rule. > > > > Don > > I got concerned one time about whether I was loosing any shadows to over > fixing and so I did a little experiment. Since I was using neutral rapid > fix (ammonium thiosulphate at pH 7.1), that's all I have data on. I > exposed > several rolls of Tri-X at zones I-X and developed them identically. I then > fixed for times ranging from 2X clearing up to 10 min. I was surprised to > find, after measuring the densities on a densitometer, that there was no > loss of density in the toe of Tri-X (zones I-III) regardless of how long I > fixed the film. I have not tried this on paper. > > My clearing times with film are mostly about 25-35 seconds but I cannot > stand to only fix for one minute so I fix as a standard practice for 3 min > with a 3 min wash aid (mostly to help get rid of the dye). > > Reasonable fixation times of 2-3 min in neutral rapid fixer will not > degrade > the image shadows. > > JB > > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >