E.L.. Shapiro wrote:
The photograph was made on chloro-bromide paper and sepia-toned. The "silvering" is caused by aging, possibly storage under less the ideal conditions, and. residual chemicals that were not adequately washed out weh they were processed. Some burnishing occurs on prints stored in albums or stored face-to-face for long periods of time.
In the olden days, the toners were sulfur based and if not washed through they were more likely to stain.
To rest the image, copying with polarized light and filtration,d a bit of contrast increase, and some retouching will make the image more displayable. Obviously, the copy will not suffer further fadeing or deterioration.
The photograph was made on chloro-bromide paper an... (
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E.L. has it pretty much correct. I have many old photographs and a few are like this.
Copy the photograph using a copy stand. Place a piece of glass over the photo to hold it flat or use a scanner.
The scanner is faster but you have more control with the raw file made with a camera. You can select the color channels on your image to assist making the image better. Generally select the blue channel or a mixture of the blue and green channels.