Sil Horwitz (silh@earthlink.net)
Tue, 02 Nov 1999 17:27:58 -0500
At 1999/11/01 09:39 PM +0000, Liam wrote: (much snipped)
>inevitable if you fix. Hovever, if instead of fixing, you place the
>bleached print in a 4% solution of potassium iodide, the silver bromide is
>changed to silver iodide which has very much lower sensitivity to light
Silver iodide is MORE sensitive to light than the bromide, but less soluble
in hypo (that's why early photographers, who sensitized their wet plates
with pot iodide and silver nitrate to make silver iodide for more
sensitivity, used potassium cyanide for fixing - it would remove all the
unexposed iodide better than hypo).
No matter what, though, a bleached silver print will go almost blank in fixer!
Sil Horwitz, FPSA
Technical Editor, PSA Journal
silh@earthlink.net
Visit http://www.psa-photo.org/
Personal page: http://home.earthlink.net/~silh/
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