Re: APIS, hydroquinone hardening

----- Original Message -----
From: "Ryuji Suzuki" <rs@silvergrain.org>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Friday, July 15, 2005 11:13 AM
Subject: Re: APIS, hydroquinone hardening

> From: Richard Knoppow <dickburk@ix.netcom.com>
> Subject: Re: APIS, hydroquinone hardening
> Date: Fri, 15 Jul 2005 01:30:12 -0700
>
>> Does this take place in any practical developer? Can
>> you
>> recommend a place to learn more about it?
>
> Practical developers for continuous tone film development
> are designed
> to avoid this phoenomenon. Sulfite-free developers,
> developers
> containing developing agents/restrainers/antifoggants in
> amounts
> away from optimal ones, etc. are easier to be influenced
> by this
> phenomenon, but it depends on the redox overpotential of
> the
> development condition and how the anode potential is
> influenced by the
> oxidized developing agents being generated in that
> particualr
> developer solution.
>
> This type of mechanism in general (electrode process
> theory of
> development) was studied in detail in 1970s and later.
> Look for
> Pontius and Willis in Photogr. Sci. Eng. in 1970s and
> Shiao in
> Photogr. Sci. Eng and J. Imaging Sci in 1980s and 1990s.
> (Earlier
> versions of electrode process theory of development were
> quite
> incomplete.)
>
  Thank you. I think I can obtain these references locally
and will do so.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com