Liam Lawless (lawless@vignette.freeserve.co.uk)
Fri, 12 Feb 1999 21:08:48 +0000
Hi Everyone,
Kodak R-21 has caused some confusion and I apologise to all concerned. I
gave the Kodak designation for this bleach in the Post-Factory article
because not to do so would be to imply that it is my own formula, which, of
course, it isn't, and someone out there is sure to recognise it, right?
I first came across it in the Kodak Data Book of Applied Photography (which
I no longer have), 5 volumes of data and instruction sheets dated from 1967
to 1973. R-21a (the bleach) and R-21b (clearing solution) were in a section
about the reversal processing of Panatomic-X film. I do not know if these
solutions were ever made commercially (though I doubt it), but I guess that
an E-6 reversal bleach would do the same job. Long time since I've done
colour, but I seem to recall that bleach-fix removes both silver and silver
halides, so no, it wouldn't work (we want only to remove developed silver).
Kodak figures prominently in the history of popular photography, and I think
it's a shame that they're not more aware of their past contributions, though
I believe they've published many formulae as alternatives to their
commercial products, and for products that they never actually sold. Years
ago, their Tech. Support department was a mine of useful information, but,
apparently, no longer. Some time ago I wanted to talk to someone about
their published selenium recipe (T-56, or was it T-55?), and despite my
listing a number of Kodak publications that contained it, the guy I spoke to
refused to accept that it was one of theirs.
Liam
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