Re: Pyrogallol staining development

s carl king (sanking@hubcap.clemson.edu)
Wed, 6 Mar 1996 15:18:55 -0500 (EST)

>
> 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