From: Judy Seigel (jseigel@panix.com)
Date: 04/01/03-10:32:49 PM Z
On Tue, 1 Apr 2003, Rauch, Shelley wrote:
>
> >>>HOWEVER, SHELLEY ! MIX UP YOUR CHEMICALS A DAY IN ADVANCE. NOBODY SEEMS
> TO HAVE NOTICED MY ADVISORY THAT VERY FRESH CHEMICALS CAN WASH OFF OR
> OTHERWISE BE GOOFY. I doubt you'd get a 2 hour exposure even at the north
> pole if everything else is in order.
>
> I purchased them at school, and then used them the very next day. I'm
> not sure how fresh they were.
It sounds from this as if you purchased them already in solution -- in
which case they're aged enough. However, you don't know how those
solutions were made or what from -- are the other students having trouble
with underexposure?
> ...We were never told what they were... just to mix up equal parts A &
B.
Great way to teach a process. (That's sarcasm.)
> >>>Did you say what paper you're using?
>
> I'm using BFK (something follows after this, but I'm afraid I don't remember).
Rives BFK is probably a slow paper for cyano -- but not THAT slow.
> We can purchase little brown bottles of the materials for $5.00 from the
> school. I actually coated 5 pieces of paper with it. Actually, when I
> say I ran out, that's not quite accurate. I ran entirely out of B, but
> A had about 1/4 of the chemical left.
That's probably about 25 cents worth of chemical...
> I told my teacher what had happened, and showed her the papers. Her
> answer: you underexposed them.
Your teacher knows less about it than you do.
However, if the other students aren't having this problem -- one thought
comes to mind. What are you using for a contact frame? I once had a
student who graduated & got a class to teach in alt photo in her area...
She called (that was pre-e-mail) for advice about setting up a light
table... She also made the kind of contact frames we used in class --
heavy masonite, foam padding, and demi-plate glass, gaffer taped onto one
side. But no matter how she tried she never got good d-max in cyano, even
with half-hour exposures.
The following month she phoned again -- ooops, she'd remembered
something. When she had the glass cut, the glazier asked in passing, "you
want UV proof glass for that?" OK, sure, thanks....
What kind of glass have you got on your contact frame?
Judy
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