In 2007 there was a very active thread here called "How was Technical Pan emulsion different?". There was plenty of fascinating insights and a general consensus that gold sensitization was part of the Tech pan story. Some commentators said Gold sensitization was the only new technology to come of of the WWII German reparations programme. I have been working for the better part of last week in the Imperial War Museum archives trying to prove this point. But what I cannot find in the published BIOS/CIOS/FIAT reports is anything about gold. The only lead is a mention of "Patent application relating to Sensitizing photographic silver halide emulsion" with the PB number 51575. Anyone familiar with this?

Koslowski said to be the father of gold sensitization is there in the intelligence record (as Korlowski) along with Dr Meuller but the record card states their papers concern Viscose production, problems of corrosion, Dyeing, viscose spinning and 'photographic emulsions' - these were microfilmed as PB70053 frames 1-971. Neither of these PB number become published reports - i.e. they don't appear in the index of the Classified List of Office of technical Services Printed Reports.


I have read:
Berg, W.F. (1979) Gold sensitization in photography. Gold Bulletin, 12, 97-98.
Ellis, P. (1975) Gold in Photography. Gold Bulletin, 8, 7-12.
Mueller, F.W.H. (1949) Some remarks on gold treatment of photographic silver halide emulsions. JOSA, 39, 494-496.

Mike Ware's take: "a number of researchers found that an even greater sensitising effect could be produced in silver halide gelatin by the addition of trace amounts of gold salts to the emulsion, but this was accompanied by a disadvantageous increase in fog. It was not until 1936 that Koslowsky, working for Agfa, found that the use of Gold (I) as dithiocyanatoaureate (I), the same substance that is formed in the gold toner mentioned above, could increase the emulsion speed while avoiding the problem of fogging. Gold sensitivity of silver-gelatin emulsions was kept secret for several years before any information was published, and the topic continues to be subject to close commercial confidentiality. The sensitization is thought to involve replacement of some of the silver atoms in the latent image with gold atoms, which are more readily reducible by the developer, but the mechanism is still a problem at the frontiers of photochemical research, which takes it beyond the scope of this book." He quotes Berg and Ellis.

Can anyone point me at a published source - or even a unpublished source! - that specifically concerns Koslowski's gold sensitization.

Sorry this post is of historic rather than practical significance but there seems to be no other forum to discuss such topics.

David Prakel