Quote Originally Posted by rongui View Post
"Overripening leads to fog and loss of speed and contrast. You must stop this ongoing process by using proper stabilizer.

I bet commercial liquid emulsions are all washed, and probably all bromide based."


I was looking at the MSDS of Liquid Light and noticed that besides the bromide and chloride, there was trace amounts of Cadmium salts.

Are the Cadmium salts used for contrast increase, reduction of fog, and would the Cadmum salts act as a stabilizer?

Just one loud remark: I AM NOT ADVOCATING USING CADMIUM SALTS IN SMALL LAB EMULSION PRODUCTION. They are very toxic and bad for the envirnment.
Do you have that MSDS in PDF form? How recent is it?

Cadmium salt is most typically used in chloride and chlorobromide emulsion. Depending on the amount, it can affect the grain size, speed, image hue, and tonality. In old formulae, Cd was used in warm tone contact and enlarging paper to increase the highlight contrast of emulsion. For this purpose, some other ripening restraining agents work just as well. Cd was also important part of lith film formula, because classic hydroquinone-only lith dev's worked best with chlorobromide emulsion of about 20-30% bromide doped with cadmium salt and sulfur sensitized (but not gold). Alternative methods were developed for this type of emulsion.

I wonder if Liquid Light is really chlorobromide using cadmium. That would be a bit surprising. Chlorobromide emulsions are much more sensitive to chemical contamination and a lot more easily ruined, compared to bromide emulsions.