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... in order to get the color tinge out of the film.
(tmy, tmx and tmz at least )
The main "side effect" is that Sodium Thiosulfate takes over three times as long as Ammonium Thiosulfate to fix film at the same molar concentration. Since T-grain films seem to be notoriously hard to fix properly (as indicated by the magenta cast that weak or used fixer leaves on the film), people tend to use the best fixers possible for these films.I'm not sure what the big deal was here. I always use regular hypo and I don't see what the side effects could possibly be.
The main "side effect" is that Sodium Thiosulfate takes over three times as long as Ammonium Thiosulfate to fix film at the same molar concentration. Since T-grain films seem to be notoriously hard to fix properly (as indicated by the magenta cast that weak or used fixer leaves on the film), people tend to use the best fixers possible for these films.
Hello PU,
I'm not familiar with the early work but here it is stated that Fox Talbot used a concentrated salt solution for fixing in his early work so yes I think fixing would be permanent:
http://www.flickr.com/groups/1924221@N25/discuss/72157629895741409/
No, it wasn't and William Herschel recommended to him at the timeto use sodium thiosulfate (hypo), which worked a ton better. Sodium thiosulfate is still the working ingredient in all commercial fixers today.Hello PU,
I'm not familiar with the early work but here it is stated that Fox Talbot used a concentrated salt solution for fixing in his early work so yes I think fixing would be permanent:
http://www.flickr.com/groups/1924221@N25/discuss/72157629895741409/
sorry this should read sodium or ammonium thiosulfate is the working ingredient in today's fixer.No, it wasn't and William Herschel recommended to him at the timeto use sodium thiosulfate (hypo), which worked a ton better. Sodium thiosulfate is still the working ingredient in all commercial fixers today.
http://www.flickr.com/groups/1924221@N25/discuss/72157629528867358/
I developed 2 test strips of Agfaphoto APX 100 for the same times in Fomadon Excel (similar to Xtol) at 23.5C.
One strip was stopped and fixed normally in proprietary chemicals.
The second strip was stopped with one wash of water at 27C then fixed for 24hrs @ 28 +/- 2 C in a solution comprising 150grams table salt in 600ml water.
The tank was kept in a warm cupboard (hot water cylinder) and agitated about every 2hrs except during 8 hrs when it was only agitated once.
Conclusion:
The print from the negative fixed in table salt solution is entirely satisfactory but held side by side with a print from the proprietary fixer negative it is slightly more grainy.
See scans of 0.1 in square sections of negative, processed identically.
I don't see why salt fixing should not be archival if carried out for long enough.
Fox Talbot stuck with quick fix salt stabilization because it gives a much better print color than the yellow obtained at long times .
https://www.photrio.com/forum/threads/fox-talbot-and-salt-fixing.141074/page-3#post-1928815
If you look at these tables, you will see that Silver Chloride is quite soluble in Sodium Chloride, but that Ammonium Chloride works even better. Silver Bromide and Silver Iodide, of course, won't be easy to fix that way, but fortunately most common table salt contains Iodide which works as stabilizer. Likewise, the Thiocyanate you mentioned as anti caking agent will rather work as stabilizer, not as fixer.
If you have to fix film and just can't possibly get your hands on any trace of Thiosulfate, I would recommend multiple bathes of concentrated Ammonium Chloride at elevated temperature, with each fixing step no longer than 10 minutes. There is no need to wash between fixing steps in such a setup.
walking in Fox Talbot's foot steps!I did a few tests "fixing" in salt about 3 years ago. The negatives have been stored in the dark and still look good but I don't expect them to be archival. The reason I did this was because I travel for work a lot and often develop film in my hotel room. I wanted to see if I could develop (caffenol) and fix (salt) film with simple store bought chemistry. I mixed up 225g of iodized table salt into 750ml of distilled water (equivalent to 300g salt in 1L), that's about all the salt that can be dissolved in the water. I let it sit at room temperature for about 48 hours giving it agitation whenever I happened by. The first image is a comparison of two negatives, "salt fix" and normal fix. So far I have not needed to do this, I usually find a way to bring some fix with me.
View attachment 194455
View attachment 194459
View attachment 194460
No, he knew what he was doing.walking in Fox Talbot's foot steps!
No, he knew what he was doing.
Wouldn't metallic Silver quickly reduce any Iodine or Iodate formed that way? At least Iodine is known to work as bleach. You will therefore end up with grains which are covered with a thin layer of Silver Iodide, and that'll be stable for a while assume it's not exposed to too much light.First the iodide disproportionates to elemental iodine and iodate ion and so is useless even if it were in amounts high enough to fix silver bromide emulsions, Same thing for thiocyanate there just is not enough present.
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