Daniel D. Teoli Jr. Posted December 17, 2021 Share Posted December 17, 2021 Is there a name for it? I've seen it on a few films. Many times, it migrates to a figure in the film. Link to comment Share on other sites More sharing options...
Premium Member Charles MacDonald Posted December 17, 2021 Premium Member Share Posted December 17, 2021 looks a bit like a redox blemish... can you provide further deails on the age of teh film and it's storage. Redox is normally associated with Microfilm, but can affect any thin emulsion B&W film. Link to comment Share on other sites More sharing options...
Daniel D. Teoli Jr. Posted December 17, 2021 Author Share Posted December 17, 2021 Age, maybe 1940s or so. I've seen it only on BW stock as far as I can remember. All the stock I've seen it on is vintage. No telling about storage. Link to comment Share on other sites More sharing options...
Daniel D. Teoli Jr. Posted December 17, 2021 Author Share Posted December 17, 2021 Film Collectors forum mentioned microfilm as well. Possibly oxidation. Also this, it covers a lot of issues. https://psap.library.illinois.edu/advanced-help/slide-film-bw Has anyone seen it on color stock? Link to comment Share on other sites More sharing options...
Frederick Knauf Posted January 7, 2022 Share Posted January 7, 2022 The damage to the image appears to be similar to what I've heard termed as "silver clad" or "silver plate-out". This is found on old black & white images of film or paper that have been exposed to high humidity and vapors that contain sulpherous compounds. The atoms from the atomosphere work there way into the image and attack the silver turning the metallic silver into silver ions and silver sulfide and the silver actually moves up to the surface of the film / paper sometimes leading to a metllic mirror-like finish on the film / paper as well. Improper fixing and washing at the time of development may leave trace chemicals inside the emulsion structure that increase the rate of decay, and other things such as handoils from fingerprints, talk spots, etc. can also affect that rate of decay. The "plate-out" seems to associate at the boundaries of heavy and light density, perhaps because the heavier density with its greater amount of silver in the remaining gel structure, acts as a giver (of silver) and as a barrier for allowing those compounds from entering the image structure. Thus, this could be considered a boundary layer problem. I do know that the earlier films did not contain overcoat layers nor the level of hardeners as do modern films; both of those to aid in reducing the migration of unwanted compounds from affecting the metalic silver of the image. This affect is not present in color film because all of the silver in color film is removed during processing. 1 Link to comment Share on other sites More sharing options...
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