Re: POP choices

[Sandy King <sanking@clemson.edu>]

>
Just as a curiosity, have you gotten enough contrast for POP with BPF 
and developers other than Pyro? My own experience with BPF is that it 
does not respond positively beyond a certain CI to increasing 
development times, period, irrespective of developer. There is 
something about this film that causes it to shut down when it reaches 
a certain CI, and prolonged development beyond this point does 
nothing but increase b+f.

Sandy King






>Hi Carl,
>
>
>This topic of pyro developed negatives to use both with POP silver and Pt/Pd
>is very interesting to me  because I've concentrated myself on this  two
>methods for contact printing and discussions about this matter are
>practically  absent.
>
>I use BPF with Rollo Pyro from Lotus View Camera in Expert drums and the
>results I got until this moment are not entirely satisfactory.
>With normal developing times  the contrast is simply not enough  for POP and
>I tried to give longer times but overall B+F+Stain  increased to a level
>that  the exposure needed to UV  is to long with the related problems.
>I've tried  as  you recommend in "The New Platinum Print" : "strengthening
>the developer and cut the developing time"  but I didn't solve the above
>described problem.
>
>Perhaps I'm missing something concerning pyro development.
>
>
>greetings
>
>Manuel Gomes Teixeira
>
>Punctum Studios
>Portugal
>EU
>
>
> > From: Carl Weese <cweese@earthlink.net>
> > Organization: Carl Weese Associates
> > Reply-To: cweese@earthlink.net
> > Date: Thu, 30 Aug 2001 11:37:26 -0400
> > To: Alt-photo-process <alt-photo-process-l@sask.usask.ca>
> > Subject: POP choices
> >
> > James,
> >
> > Assuming you will have access to a darkroom for film development (4x5
> > film in trays doesn't take much space): FP4+ in PMK pyro will give you
> > negatives you can print in POP silver, and then later print in Pt/Pd or
> > on standard variable contrast silver paper. Pretty good combination. It
> > gives high acutance if that's what you're after. As for obtaining it in
> > Japan, just take a couple dry packaged kits from ArtCraft Chemical with
> > you. Each will make 50 liters of working solution which is enough for an
> > enormous number of 4x5's. The mixed stock solutions have excellent shelf
> > life. Tri-X/PMK is another good pair. TMX and HP5 are more trouble
> > getting enough contrast for POP processes. Of course observe proper
> > precautions for handling pyro which is more toxic than more ordinary
> > developers.---Carl
> > --
> > Web Site with picture galleries and workshop information
> > http://home.earthlink.net/~cweese/index.html