From: Sandy King (sanking@clemson.edu)
Date: 02/02/03-09:42:46 PM Z
Judy Seigel wrote:
>
>> With most forms of kallitype, as well as platinum and palladium,
>> exposure forms only a whisper of an image, much too faint to cause
>> much self-masking. The same would appear to be true of cyanotype.
>
>Sandy that is absolutely not true. I knew it wasn't true & you have cost
>me 20 minutes of my remaining time on earth to again prove that it wasn't
>true. That is, a cyanotype exposed but not developed showed density in
>the darkest shadows equal to number 9 out of a possible 19 on the Kodak
>Gray scale. I consider that substantial, not "too faint to cause much self
>masking."
Judy,
A couple of more comments about this.
First, I just wanted you to be absolutely clear about the meaning of
my message above on cyanotype. I am sorry that you spent any amount
of time trying to prove that what I said was not true because I think
you simply misunderstood my message. Anyone who has every made a
cyanotype, and though I am no expert by far on the process I have
made a few, knows that there is quite a lot of print-out that appears
during exposure, so about that we have no misunderstanding at all.
Really, one would have to be blind to not be aware of that so I would
have thought it would have been clear that this was not my point. My
point was/is that the print-out image, however strong it may be
visually, is still too faint to cause much self-masking.
>
>The other thing that's baloney (I wonder did they ever actually TEST or
>just THEORIZE!!) is the business about the blue color passing light
>through because -- what -- not actinic sensitive? I forget the jargon.
>Whatever, I stuck in 2 little pieces of light blue gel, separately and
>overlapped -- and guess what -- yeah, definitely lighter in those areas.
>As noted, this took all of 20 minutes & I'm not even writing a book.
>
I don't understand your results but the premise of your test has no
validity in my opinion. Adding a piece of light blue gel between the
exposing light and the print is going to cut some exposure. You can
never increase the amount of radiation reaching the paper by adding
filtration because whatever you add is going to cut radiation rather
than add it. And adding two pieces of blue filter will reduce
radiation more than one piece, so if I understand correctly the
results of your experiment the lighter color was perfectly
predictable. However, the situation of your test is not analogous to
the theory that has been advanced by some others to explain why there
is no self-masking with cyanotype. As I understand it, the theory is
that the blue image color offers less actinic filtration than that of
the silver metal of a POP or salted paper print.
I must admit that I have not studied cyanotype enough to make any
definitive statements about it so if you have any proof or evidence
that there is a significant amount of self-masking going on please
feel free to prove me wrong.
Sandy
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