[alt-photo] Re: Collodio-Chloride and Collodion-Based Silver-Chloride Processes: Strontium-Chloride vs Sodium Chloride?

[Ryuji Suzuki]

I don't have experience with collodion process but in silver gelatin process, 
the counter ions in the halide jet don't matter, as long as they are alkaline 
metal or alkali earth metal ions, impurities are well controlled, and the molar 
concentrations are adjusted. Those cations are just wasted without participating 
in any reaction that forms silver halide crystals. If solubility in alcohol is a 
factor, that may be one thing, but then what alcohol concentration are you 
talking about? In silver gelatin, sodium, potassium, and sometimes ammonium ions 
are used. Ammonium ions have different effects on silver halide crystals in a 
pH-dependent manner, but Na and K are largely irrelevant (in most cases, they 
are removed from the emulsion before chemical sensitization phase).

Emulsions that are used for printing out processes are very different from 
emulsions for developed out processes. Don't underestimate that difference.

I also would not put too much emphasis on stuff written in old literature, 
unless you can validate the statement with modern science. Systematic research 
of how emulsion crystals are formed and what factors have influence, etc., had 
to wait for sensitive instrumental amplifiers, electron microscopes, and various 
laboratory equipment in the 20th century. If certain issues or terminology 
disappeared in later literature, it might be because the earlier debate became 
irrelevant under the light of new science. THere are countless examples like that.

-- 
Ryuji Suzuki
"When you're finished changing, you're finished." (Benjamin Franklin)