RE: fixing van dyke brown AHEM!!!!!
Chris, > I diluted paper strength fix by half and I did not see any bleaching. Am I the only one that sees it this way? Or maybe it is just on Weston that it doesn't bleach? I fixed for 2 minutes, after a 2 minute water bath. > Perhaps a definitive answer would be to test sodium thiosulfate fixer normally used for VDB against your diluted ammonium thiosulfate mixture using prints of step wedges. Assuming that the paper strength fixer was mixed from concentrate at a 1 to 9 dilution, diluting that by half would be roughly equivalent to a 5% dilution. Looking at a rapid fix formula sold by Photographers Formulary as a guide, about 1 liter of 60% ammonium thiosulfate will make about 8 liters of working paper fix which would produce roughly a 7.5% solution of ammonium thiosulfate, halving that would yield a 3.75% solution or there about. Of course there are other chemicals used and the PF produces a fixer with a pH of about 6.5. Perhaps the addition of sodium carbonate could be used to make the fix alkaline, ostensibly to further reduce the possibility of highlight bleaching. But this is all conjecture on my part. Where is Ryuji when we need him? And there is also the question about how to determine the proper fixing time to ensure a minimum amount of residual silver salts left in the paper. My guess is that the Weston paper being so light in weight would fix very quickly, much more easily than a heavier paper, but again conjecture on my part. > Did I also say it was made from recycled blue jeans? Recycled blue jeans? Where did you hear that? Don Bryant
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