Archived posting to the Leica Users Group, 1999/05/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]George Huczek wrote: > > At 10:23 AM 10/05/99 -0700, Mark wrote: > The new Anchell/Troop book > >says Sodium Thiosulfate is no longer recommended for modern films and > >probably "will not do the job"!! > > Sorry Mark, but this is complete hogwash! The only difference in the > result you get with ammonium thiosulphate and sodium thiosulphate has to do > with the time needed to complete the job, not the effect. Ammonium > thiosulphate is faster, hence the name for its concoctions -- rapid fixer. > It is the thiosulphate ion that complexes to remove the unreduced silver > ions from the film or paper. The cations join with the halides to produce > a partial restraining effect, which becomes irrelevant if fixing time is > sufficient. > Give me the exact quote from the Anchell/Troop book that you are > referring to and convince me (and others) that standard hypo, which has > been used for nearly as long as photography itself, can no longer "do the > job" as you put it. > > _ > [o] -GH Ammonium thiosulphate is a much more active and therefore faster silver solvent and it used to be uncool to use it by the hard core guys/gals who I assume thought it would strip your silver away in it's exuberance... then came the Ilford 30 second double strength fixing theories and it was a whole new ballgame. Anchell/Troop are saying that it is POSSIBLE that some modern films are made so sodium thiosulphate would not ever do the job. This was a tentative assertation. They are saying modern (T Grain) films are "harder" but they are not saying that definitely and if they ever do I'm not saying I'll believe them. They have said plenty that I've had differing experiences with but they have come up with a whole lot of exciting stuff. The washing of hogs would not apply substantially to them or my referals to them. I am looking forward to purchasing my first bulk 5 pound batch of old fashioned Hypo (which is sodium thiosulphate or Fixer for those not up on it) But its use would be for printmaking and especially in line toning as the longer fixing times would match longer toneing times. Mark Rabiner Oink Oink splash splash click click!