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Old 10-19-2007, 12:22 PM   #5 (permalink)
Ian Grant
 
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Join Date: Aug 2004
Location: Turkey (West Midlands, UK)
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Ron, I totally agree with your points. Back in the 70's/80's when I manufactured emulsion commercially I initially used active gelatins but switched to de-activated gelatin and added sulphur compounds. This gave better speed and contrast.

The old Agfa paper formulae are useful because it's fairly easy to see how different grade emulsions were made. As Ron and I have discussed in other threads some of the chemicals used are now banned for commercial use (cadmium salts).

Ian
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