Actually, the Russian developers, AKA solvent-physical developers (which consist of a „normal“ developer to which a small amount of silver halide solvent has been added), seem to go back at least to Richard Neuhauss, the Lippmann photography guy.Joe Farina wrote: I have always been interested in these types of holograms, though I never had one (I would like to). I guess this is really a Russian technique,
Incidentally, the same kind of colloidal layer effect can also be achieved by physical development.
I guess the first attempts date back to Denisyuk/Protas. They did apply the old Valenta developer (used for Lippmann photographs) to holographic emulsions.and I have wanted to ask our Russian friends about the history of colloidal development of holograms (wasn't it pioneered by Usanov?)
[/quote]I would also like to know if the assumed non-printout quality of colloidal holograms has been proven over many years of observation in Russia.
Yes, I'd also love to hear more about that.
Last year, when I received some of the new AgX films produced by Valery Smirnov, I put one colloidal developed hologram on the window board. It stayed there, exposed to direct sunlight for several months. The hologram remained completely stable, I couldn't detect any darkening of the layer.