From: Gwen Walstrand (gwalstra@lib.drury.edu)
Date: 04/17/00-07:17:28 AM Z
Bob,
Thanks for the info. I was hoping someone had tested this thoroughly so I
wouldn't have to at this busy time of the semester. We have had good
results with the 2:1 solution but it didn't seem to shorten the exposure
time.
I neglected to mention in my last message what the actual exposure times
for cyanotype are. They are typically one hour (or more) for a film
negative and about 50 minutes for an inkjet negative. We may try the sun
next. Thanks for your help.
Gwen
>Gwen,
>
>Last spring I ran some extensive tests on cyanotype and found that
>using a sensitizer of 2 parts A to 1 part B gave the greatest
>tonal range. I was using a 21 step tablet and controling everything.
>When compared to the Ware process the results were nearly equal
>although the Ware process did have a slight edge as to tonal range.
>
>Your exposures sound about right to me. Of course a lot depends on the
>negative density. The only way I know of to decrease the exposure
>would be to use a stronger UV source. You might try using the sun.
>
>Bob Schramm
>
>>From: Gwen Walstrand <gwalstra@lib.drury.edu>
>>Reply-To: alt-photo-process-l@sask.usask.ca
>>To: alt-photo-process-l@usask.ca
>>Subject: cyanotype sensitivity
>>Date: Sat, 15 Apr 2000 17:39:18 +0100
>>
>>I am wondering what are typical exposure times for cyanotype and whether
>>there's a way to speed up the sensitivity. Does the 2 parts A solution to 1
>>part B solution give greater sensitivity as well as greater tonal range?
>>
>>I teach an alternative processes class that uses a 1500 watt metal halide
>>plate burner (the very low end of the plate burner market, manual
>>shutter...). The light source is placed about 30 inches from the vaccuum
>>table for greater coverage. Our typical exposures for Van Dyke, Gumoil,
>>Kwik Print and other processes are all between 4 and 8 minutes. Cy anotype
>>exposures create quite a bottleneck in the classroom. Any suggestions for
>>speeding up the exposure times?
>>
>>Thanks in advance,
>>Gwen Walstrand
>>
>>
>
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