No, you do not lose the image. The latent image is still there as silver metal and can be revealed by the proper process. This is outlined in the patents on catalytic imaging in which the silver halide is totally removed leaving only the latent image. That silver is then amplified to give a normal speed/contrast H&D curve.
PE
Hummm...
I did say
"putting aside the possbility of physical development for the moment".
Are you saying that with normal chemical development...
you can develope a latent image... with out the presence of the silver halide?
???
Yes, it is in the patents!
PE
Ian, I would be surprised to learn of contemporary commercial developers for pictorial film that employ ammonium chloride. Could you name some of the ones you refer to?
can anyone spot what is wrong? There will be a prize.
Ian, and subsequently RobertV, thank you very much for the references to modern developers with ammonium chloride. I have been studying these. I was also very surprised to find thiocyanate being used in the manner of DK-20. One of the great weaknesses of FDC, as I mentioned earlier in this thread, is that it does not address the photochemical work being done in Europe, particularly Germany. I knew this was a problem from the start, but frankly, I thought I was doing enough internationalization by giving Crawley's work the attention it deserves, which had never been done by an American writer before or, for that matter, a British writer. Regardless, it has been a great pleasure to look at the ingenious formulas from Rollei and Spur, apparently by Raffay, that have adapted some of these old-fashioned solvents for use with modern materials. It is not how I would do it, and I think there are better chemicals to use, but I am still very impressed.
Ron - - re Henn's beard, he only grew it after he retired. He told me it caused a lot of raised eyebrows in Rochester. Not to mention his becoming a painter. Quite a lifestyle change!
In the early 1960s when Crawley was writing his little masterpiece for the BJ, the gold standard for evaluating a developer's proclivity to dichroic fog was Royal-X, the then-fastest, coarsest-grained film available. What film, today, is the most sensitive to solvents?
..What film, today, is the most sensitive to solvents?
A good substitute easy formula for Microdol-X:
A good substitute easy formula for Microdol-X:
Also the same formula I've mentioned. See my post
163 this thread. I've included the source. Dan
Did you read the whole thread? If you didn't, you should. I found it most interesting. Much of the talk is about adding chlorides to developer formulas. There's a note in The Darkroom Cookbook about D-25 that states: "If it is not essential to obtain minimum graininess use half the quantity of sodium bisulfite". That would be the formula you're giving.
Sorry
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