From: Eric Neilsen (e.neilsen@worldnet.att.net)
Date: 12/23/00-10:08:19 PM Z
DAVID DISTEFANO wrote:
> First off I would like to wish everyone Happy Holidays and a Fantastic
> and productive New Year.
>
> Question: Last night I was experimenting and decided to try a ziatype
> print from a 5x7 negative that was made for silver printing.
>
> I first did a straight print using 6 drops of AFO and 6 drops of LiPd.
> The high values were right at six minutes but the deeper tones were very
> weak. This was to be expected. I then added a drop of 5% ammonium
> dichromate. To reach the high value that I wanted, took an exposure of 1
> hour. At this exposure the deep values fell into place. One problem
> showed up. The print looked like a print from the Civil War. The sky had
> a very mottled look, from white to medium gray.
>
> What was the cause of this? The sky is uniform in value on the negetive
> and the print without the a/d. as well as the silver print. The negetive
> is a pyro negetive and the silver print was made on a grade 3 fiber
> based paper.
>
> Thanks
> David.
>
> P.S. I want to publicly THANK Carl for all the help he gave me 2 weeks
> ago. There aren't many people who would spend the time like he did
> answering my questions via e-mail.
>
> Thank you again Carl
> David
David, While it may not be a Zia family answer, I would
recommend trying a bit of ammonium platinum salt. It has a
very high level of platinum in solution and will greatly
increase the contrast. I also find that LiPd has a tendency
to produce prints that have a slight haziness to them. This
will also clear that up. If you are using an hour long
exposure, I would also agree that you are fighting the low
level of humidity. The platinum will also help with that as
it is much faster at low levels of humidity than is palladium.
I have not tried the newly touted Sodium based platinum. In
reading Dick's paper and the follow up article, I failed to
see any comparison to ammonium based platinum, only the
"standard" potassium based platinum.
EJ Neilsen
-- Eric J. Neilsen 4101 Commerce Street, Suite #9 Dallas, TX 75226 214-827-8301 http://e.neilsen.home.att.net http://www.ericneilsenphotography.com
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