Re: Pyrogallol staining development

Keith Schreiber (KEITH@ccp.arizona.edu)
Wed, 06 Mar 1996 21:01:41 -0700 (MST)

On 7 Mar 96 s carl king wrote:

> >
> > I have used his recipe for some time and have found that the
> > negatives processed in PMK pyro developer, maintain the beautiful
> > highlight details in subjects such as clouds, scenes where I would
> > like to maintain the *real* texture of snow (of which we do get our
> > fair share). There is no comparable developer. The pyro tanning
> > (stain) is produced in proportion to the amount of silver developed.
> > When processing, the negatives are PUT BACK into the developer
> > AFTER fixing and they *develop* that nice yellowish stain so
> > reminiscent of the *old* negatives
> >
> > Ken
> >
>
> I too am very fond of PMK for some of the same reasons mentioned
> above. With 35mm and roll-film negatives processed in PMK can
> have wonderful tonal gradations and great apparent sharpness.
> Processing sheet film can be something of a problem. Tray processing
> works fine but you must use gloves with Pyro because of its toxicity
> and I always wind up scratching my negatives with gloves. Processing
> in tubes like the BTZS tubes often does not work well because the back'of the
> negative does not come in contact with the developer, which results
> in uneven of the gelatin, or perhaps none.
>
> For the alternative processes the greatest problem with Pyro developed
> negatives (and this was mentioned a few months back in another thread)
> is that the yellowish stain functions like an actinic filter and
> causes exposures to be much longer than with conventionally processed
> negatives. You can minimize the staining by using a hardening fixer and
> not running them through the used developer after fixing but this
> eliminates some of the good things about the developer.
>
> I would be interested in hearing from others regarding their
> experience with PMK in terms of a) developing technique and b) exposure
> times with the alternative processes relative to negatives processed
> with non-staining formulas.
>
> Sandy King
>
I experimented with PMK Pyro a few years ago and my experience
regarding printing times concurs with John's - an increase in
exposure time of about 100%. At the time I was using HP5+ and TXP.
I also did not find the pyro negatives to have those almost mystical
qualities some claim for it. In comparative tests I nearly always
prefered the other. For the past 2 years I have been using TMX
developed in D23 (A+B where B is 1% Kodalk) with much success.

Keith