From: Joe Portale (jportale@gci-net.com)
Date: 02/12/02-11:24:48 AM Z
I don't know about "speeding up" Calotypes, but there is several chemical
methods for Salted Paper. Understand, none of these will increase the speed
more than a half stop. One involves ammoniating the silver nitrate (not that
hard, but many steps). The second involves boiling the paper (before
sensitizing) in a 10% solution of potassium chlorate. When the paper is
dried, coat with the silver nitrate solution. The keeping properties of this
method are poor, it must be exposed as soon as the sensitized paper is dry.
It doesn't fix well either. I experimented with this for a time and could
not get the print to properly fix. A third, is to replace the salting
solution with muriatic acid. Like, I said it only gains about 1/2 stop
speed. The hazards do not out weigh the benefits. Another technique, if you
can make it work is to under a darkroom safelight, coat the paper with a
18-20% solution of potassium bromide. When damp dry, coat with the silver
solution. Dry in the dark. Contact expose as usual. If you get an image, it
will have a very nice detailed blue-black color. I am using "if" because
this is a VERY temperamental way of doing things. At one point I was able to
make six very nice contact prints, then for no reason at all, the process
stopped working. Terry King and I tried to collaborate to get this
bromide-silver technique to work and we kept banging our heads on the wall.
Joe Portale
Tucson, AZ
PS. If this post didn't make sense, my apologies. I'm fighting the flu and
am very cloudy minded.
----- Original Message -----
From: "Richard Morris" <Richard.Morris@brunel.ac.uk>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Tuesday, February 12, 2002 1:42 AM
Subject: Re: Speeding up salt prints & calotypes
> Firstly wet and dry plates ain't calotypes!! These are images made on
paper
> negatives to Talbot's discovery of 1840.
>
> That said the fastest known calotype exposure was 1 second about 1852 by
> Nicholas Henneman. I forget, without looking up my files as I am
> not replying from home, if it was an image of a girl or a Hungarian, said
> to be Kossuth. One was three seconds and the other one. I have seen both
> images and a letter from Talbot sending them to John Dillwyn Llewelyn.
>
> Malone was said to be experimenting with some French paper, which may have
> given faster exposures, and we don't know what lens Henneman used either.
> On average 2 minutes at f8 was quite reasonable. I have done one in 3
> seconds using Talbot's portrait camera with a lens of around f1.6 but it
> wasn't very good!
>
> Calotypists also used to play around with the proportions of chemicals
> depending on whether they were using the paper immediately or later. More
> gallis acid preserved the paper but apparently reduced the sensitivity. I
> feel that it is worth trying different proportions as modern papers don't
> have the same properties as Talbot's and probably chemicals are now purer
> which may or may not help. I can say that different makes of silver
nitrate
> do make a difference by wbhy I don't know.
>
>
> With salt paper, Talbot's original Photogenic Drawing process of 1834/5,
> announced in 1839, he used to resensitise the paper several times, until
> just before it became darkened spontaniously, and found that way that it
> was more rapid. He also, just prior to the discovery of the calotype, used
> to add a few drops of gallic acid.
>
>
> Richard Morris
>
>
>
>
> On Tue, 12 Feb 2002 09:16:35 +0100 (CET) "=?iso-8859-1?q?F.=20Wentzel?="
> <fotochemiker@yahoo.de> wrote:
>
> > --- Martin Reis <mreis@tafelmusik.org> schrieb: > Hi
> > there,
> > >
> > > I am somewhat new to the alt processes and wonder if
> > > there are any simple
> > > ways to speed up salt prints, wet and dry plates
> > > (calotypes). Can a chemical
> > > be added to
> > > speed up sentiziation. That is using that fastest
> > > light
> > > sources available. Just got my copy of Primitive
> > > Photography and the
> > > processes described in it seem
> > > quite slow.
> > >
> > > Cheers
> > > Martin
> >
> > __________________________________________________________________
> >
> > Gesendet von Yahoo! Mail - http://mail.yahoo.de
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>
> Richard Morris
> Brunel University, UK
> dtsrrlm@brunel.ac.uk
>
>
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