RE: bronzing in pt/pd

Palladium, being less reactive at low humidity, would require more exposure
to form an image. I would expect the problems with Palladium and
bronzing/solarizing to be greater at low humidity. Did you check it with any
PT added? What mix of LiPd did you use? Did those test include AFO as well
as FO?

Eric Neilsen Photography
4101 Commerce Street, Suite 9
Dallas, TX 75226
214-827-8301
http://ericneilsenphotography.com
 
Skype : ejprinter
> -----Original Message-----
> From: wcharmon@wt.net [mailto:wcharmon@wt.net]
> Sent: Thursday, April 06, 2006 1:31 PM
> To: alt-photo-process-l@usask.ca
> Subject: RE: bronzing in pt/pd
>
> Different types of metal salts can have different propensities
> toward
> bronzing. I actually ran some step tablet tests a few years ago
> that proved
> this to my satisfaction. The worst in my experience is Lithium
> palladium when
> used as a DOP metal salt. It almost always requires double
> coating. Ammonium
> palladium seems to have the least propensity for this. I have
> also noticed
> (but not tested rigorously) that humidity plays a role. I
> notice that bronzing
> is much more likely when the ambient humidty in my darkroom is
> below 30% than
> when it is closer to 50%. Since I live in Houston, 50% is more
> the rule than
> the exception!
>
> Clay
> Quoting Eric Neilsen <e.neilsen@worldnet.att.net>:
>
> > They are directly related but also with the type or mix of
> coating being
> > applied. PD is much more likely to bronze than platinum, but
> a thin coating
> > will do it, I have not seen or do not recall seeing, a well
> coated print do
> > it. You can also see it if you have an imbalance in the
> coating solution;
> > too much ferric for too little metal salts.
> >
> > Eric Neilsen Photography
> > 4101 Commerce Street
> > Suite 9
> > Dallas, TX 75226
> > http://e.neilsen.home.att.net
> > http://ericneilsenphotography.com
> >
> >
> > > -----Original Message-----
> > > From: Christina Z. Anderson [mailto:zphoto@montana.net]
> > > Sent: Thursday, April 06, 2006 9:14 AM
> > > To: alt-photo-process-l@usask.ca
> > > Subject: Re: bronzing in pt/pd
> > >
> > > So what y'all are saying, Eric, Don, Jeremy, is it is as
> much exposure as
> > > thin coating, and the thinness just created more of an
> exposure issue??
> > > chris
> > >
> > >
> > > > Chris, If you are having your students coat and print
> with brush
> > > strokes
> > > > that show it will be easier to see some on many prints.
> It is easily
> > > done
> > > > with the use of a brush; foam or bristle. You can feather
> the edges of
> > > the
> > > > overcoated area, that where the neg presumably won't be
> placed, to allow
> > > > for
> > > > some very thin areas. If thin were the only the answer
> you could see it
> > > > all
> > > > over the place where thin coated areas were present. It
> also has to do
> > > > with
> > > > coating solution used. If you are only using PD it will
> appear more
> > > often,
> > > > but can happen with PT as well.
> > > >
> > > > Thinner coatings are faster than thick ones but are also
> less able to
> > > hold
> > > > the exposure before bronzing/solarizing (old expression).
> > > >
> > > > Eric Neilsen Photography
> >
> >
> >
>
>
>
>
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
Received on Thu Apr 6 12:55:43 2006