[pure-silver] Re: Pyro Was: Re: AW: Re: Any advice for purchase ofdensitometer.
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Sun, 26 Dec 2004 16:47:39 -0800
----- Original Message -----
From: "Ryuji Suzuki" <rs@xxxxxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Sunday, December 26, 2004 2:59 PM
Subject: [pure-silver] Re: Pyro Was: Re: AW: Re: Any advice
for purchase ofdensitometer.
> From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
> Subject: [pure-silver] Re: Pyro Was: Re: AW: Re: Any
> advice for purchase ofdensitometer.
> Date: Sun, 26 Dec 2004 14:18:37 -0800
>
>> For bleach and redevelopment intensification a low
>> sulfite developer should be used. A standard film
>> developer
>> may have enough sulfite in it to dissolve some of the
>> rehalogenated silver produced by the bleach and actually
>> lose some density. The best redevelopers are print
>> developers like Dektol. The grain of the final image is
>> not
>> much affected by the developer.
>
> Print developers are probably enough, but if you make a
> batch just for
> this application, I'd leave out bromide, benzotriazole,
> 6-nitrobenzimidazole, 1-phenyl-5-mercaptotetrazole, and
> any other
> antifoggant, and also choose phenidone based developer.
>
> The *ideal* developer is one of the fogging developers
> sometimes used
> for reversal processing. The silver halide crystals made
> by bleaching
> process is very defective in terms of crystalline
> structure, and I bet
> those crystals are high in fog and low in sensitivity.
> Chemically
> fogging them is probably the best way to ensure all silver
> is
> developed again.
>
> --
> Ryuji Suzuki
> "Keep a good head and always carry a light camera."
I wonder if a sulfide bath would do. Of course, this is
no more than sepia toning. Sulfide is suggested as an
alternative redeveloper for reversal and does not need the
final fixing bath usually recommended otherwise. This
suggestion is made only because the fogging agents used in
reversal color processing do not seem to be readily
available. However, can you suggest one that would be
suitable for addition to a standard developer or, perhaps, a
suitable redeveloper formula. This would be useful both for
intensifying and for reversal processing.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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