Archived posting to the Leica Users Group, 1999/05/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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