U of S | Mailing List Archive | alt-photo-process-l | RE: argentotype again

RE: argentotype again



Alberto,
I you read Willis original patent, which  I can't remember if it is dated 1913 or not, the process that he describes as satista (and I am not sure if he uses that name or not) is not what we call "satista now". His process involves sensitising silver halide emulsion with platinum, exposure with UV and development in POTA developer. I tried sensitising silver chloride paper (Forte wt) with Pt salts and it workes OK. I need to reread the patent again as it has been a few years. I never followed his recipe as described in the patent, but I would think it would work OK as my crude attemt to sensitize commercial paper gave decent results.
Marek 
 
> Date: Thu, 21 May 2009 07:53:55 +0200
> From: alt.list@albertonovo.it
> Subject: Re: argentotype again
> To: alt-photo-process-l@usask.ca
>
> Marek,
> this thread, in practice, never started... I was asking if anybody knew the
> formula of Herschel's argentotype, but I haven't had any reply. It was for
> historical purposes only, as I were writing some notes for a school.
> Yes, the principle (sensitive substance in the first coat only, reactive
> substance in the developing bath/coat) is the same as satista, cyanotype
> Rex, Namias' kallitype, etc. The differences with satista are the fe. am.
> citrate instead of fe. oxalate and silver nitrate instead of platinum.
> Herschel devised this in 1842, Willis (satista) in 1913.
>
> Alberto
>
>
> > ALberto,
> >
> > Somehow I missed the thread, but it sounds like the satista process that I described on the alternative photography web site
> >
> > http://www.alternativephotography.com/process_satista.html
> >
> > Marek
> >
> >> Date: Wed, 20 May 2009 09:56:47 +0200
> >> From: alt.list@albertonovo.it
> >> Subject: argentotype again
> >> To: alt-photo-process-L@usask.ca
> >>
> >> I've had a reply offlist from Mike Ware (he is not subscribing) about the
> >> argentotype recipe. See below.
> >>
> >> Alberto
> >>
> >> -------------------
> >> Dear Alberto,
> >>
> >> Your outline description of Herschel's argentotype is correct - but I
> >> cannot add much in the way of further details. In his 1842 paper to Phil.
> >> Trans. he only mentions it in the Postscript, Art. 218, on p. 210. Here is a
> >> copy of Herschel's original text:
> >>
> >> 218. If paper prepared as above recommended for the chrysotype, either with
> >> the ammonio-citrate or ammonio-tartrate of iron, and impressed, as in that
> >> process, with a latent picture, be washed with nitrate of silver instead of
> >> a solution of gold, a very sharp and beautiful picture is developed, of
> >> great intensity. Its disclosure is not instantaneous; a few moments elapse
> >> without apparent effect; the dark shades are then first touched in, and by
> >> degrees the details appear, but much more slowly than in the case of gold.
> >> In two or three minutes, however, the maximum of distinctness will not fail
> >> to be attained. The picture may be fixed by the hyposulphite of soda,
> >> which alone, I believe, can be fully depended on for fixing argentine
> >> photographs.
> >>
> >> He does not specify the strength of the Fe am cit solution in this paper,
> >> as you will see from the quotes in my "Gold in Photography" pp 68-74, but I
> >> have discovered elsewhere that he used 1 part of Fe am cit to 9 parts of
> >> water, typically. I do not know the strength of his silver nitrate
> >> solution.
> >>
> >> I have seen some of Herschel's argentotypes, at Oxford, Bradford, and at
> >> HRHRC Texas, and they are faded, compared with his original description. I
> >> think he made very few of these iron-based silver prints.
> >>
> >> Best wishes,
> >>
> >> Mike
> >>
> >>
> >> On 16 May 2009, at 11:45, Alberto Novo wrote:
> >>
> >> > All I know about argentotype is that it was a (presumabily) Fe am
> >> > citrate coating developed in silver nitrate. I have a Namias'
> >> > formula for a brown-black callitype developed in alkaline silver
> >> > nitrate which might be a more refined approach, but I would prefer
> >> > to cite the original formulation.


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