From: Eric Neilsen (e.neilsen@worldnet.att.net)
Date: 01/21/02-11:10:51 AM Z
Jeffrey, I would have a darkroom in the 40's to work in. The months of
January and February nights would get down in the 0 F to 10 F. The
correlation between temp and RH is quite important. As you point out, the
effects of high RH are reduced when the temp is low. A low RH is also
lowered when heating a room. This is why I recommend getting the room back
up to a reasonable temp ( low 60's is ok), and if one is to conduct
"tests", I would try and run those test at same Temp/RH settings as before.
My darkroom in Taos had a wood burning stove as well as base board electric
in it, so I needed to take much into consideration when getting ready to
print.
It has been sometime since I worked with a cold darkroom. I would also
suspect that there is quite a range for different papers and coating
techniques. When living in the San Francisco Bay Area, we dried the Cranes
paper in the dry mount press for a few minutes before printing to lower its
moisture content as our lab was right in the path of a rolling fog bank that
covered the area and raised the RH considerably.
I have not tried coating in temps in the 80's with high humidity in quite
some time.
Eric Neilsen
Eric Neilsen Photography
4101 Commerce Street, Suite 9
Dallas , TX 75226
214-827-8301
Web Sites : www.ericneilsenphotography.com
http://e.neilsen.home.att.net
----- Original Message -----
From: "Jeffrey D. Mathias" <jeffrey.d.mathias@worldnet.att.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Sunday, January 20, 2002 4:24 PM
Subject: Re: PT/PD temp/humidity
> Nick Makris wrote:
> > ... the temperature is currently 58F deg in my darkroom. Anyone know >
or care to
> > guess what differences I can expect between that and my normal
> > temp of 68F ...
>
> I will have to disagree with both Eric and Carl in that I have found the
> coating and exposure of Pt/Pd to be better at 60F or the upper 50s. The
> real trouble starts when the temperature gets above 70F and especially
> above 80F.
>
> As far as low temperature I would expect some limit to how cold the
> processing can be performed at, but do not have information on this.
> For coating and exposing, the lower temperature gives better
> consistency, and produces better all round results in image quality.
> And lower temperature is even more important when the RH is higher.
>
> --
> Jeffrey D. Mathias
> http://home.att.net/~jeffrey.d.mathias/
>
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