Photograph of Marie Curie Processed with Uranium Toner
Over the years, uranium has had a variety of applications in the
photographic industry, but its most common use has been as a toner. The
print shown in the photo to the right was treated for ten minutes in Kodak
Uranium Toner K-9. It now contains about 3 milligrams of depleted uranium.
The toning replaced some of the silver in the original print with uranium
thus causing the image to change progressively from black to reddish
brown. The surface activity in the darkest areas is approximately 160 cpm
above background as measured with a 2" pancake GM probe. How much
uranium would end up in the final image would depend on how long the print
was left in the toner and how dark the image was.
While not certain, it is possible that some of Ansel Adams' original prints were treated with uranium toner - the latter was apparently found in his darkroom after his death. Unfortunately I have not been able to locate any references to uranium toner in his books.
Adams often photographed landscapes in the same areas where uranium was
mined. It would certainly have had a touch of poetry about it if any of his
photographs incorporated uranium that came from the area where the
photograph was taken.
There are various formulae for uranium toner. Here is one:
Produced and donated by William Kolb
Copyright 1999, Oak Ridge Associated Universities