Re: Phenidone in Pyrocat-HD

From: Sandy King ^lt;>
Date: 03/04/05-09:16:31 AM Z
Message-id: <a06020420be4e2979c30b@[]>

I did these experiments some seven or eight years
ago and have since lost my notes, but as I recall
the use of pyrocatechin as the only reducer
resulted in much longer development times, less
effective film speed and very large grain, but
very good acutance. In those tests I remember
that I used pyrocatechin in amounts ranging from
about 0.5g up to 4.0g per liter of working


>And what was the result with Pyrocatechine only?
>>From: Sandy King <>
>>Subject: Re: Phenidone in Pyrocat-HD
>>Date: Fri, 04 Mar 2005 09:12:13 -0500
>>The first Pyrocat-HD formula used metol as the
>>synergism agent, but when I experimented with
>>phenidone I found that it gave slightly greater
>>effective film speed and somewhat finer grain.
>>The difference is very small and many people
>>who mix their own Pyrocat still use metol. The
>>substitution of metol gives, based on my own
>>experience, a slight increase in acutance,
>>assuming the same type of agitation, but at
>>the expense of EFS and grain.
>>>First I would like to thank you for your answer.
>>>I have another question about Pyrocat-HD. In
>>>fact I would like to know why did you choose
>>>Phenidone for second developping agent and not
>>>another? Is it in relation with its property
>>>to give low contrast?
>>>Thanks again.
>>>Delphine Chapuis
>>>>From: Sandy King <sanking@CLEMSON.EDU>
>>>>Subject: Pyrocat-HD Developing times
>>>>Date: Thu, 17 Feb 2005 11:09:14 -0500
>>>>Hi Delphine,
>>>>You can find Pyrocat-HD developing times for
>>>>several films, including FP4+ and BPF 200, at
>>>>the end of the article "An Introduction to
>>>>Pyro Staining Developers, at
>>>>This article was translated into French as
>>>>"Introduction aux révélateurs colorants au
>>>>pyro" and is in the French language site
>>>>Galerie-Photo, at
>>>>That data for FP4+ is very sound and his been
>>>>consistent with several different testings of
>>>>different emulsions. I can not say the same
>>>>about BPF 200, however, as my testing has
>>>>given some rather wide variations in results
>>>>with different emulsions of this film.
>>>>Let me know if you have any questions.
>>>>>I'm developping my film for a palladium
>>>>>process (Mike Ware's) but in fact I just
>>>>>need standard (universal) developping times.
>>>>>I explain me: I am a student at the Ecole
>>>>>Nationale Supérieure Louis Lumière (France)
>>>>>in photography and I want to study the
>>>>>effect of the stain with these films on a
>>>>>multigrade process. In fact my aim is to
>>>>>make dual purpose negatives but to assign
>>>>>the development in priority to the palladium
>>>>>I will have to test pushing and pulling
>>>>>development and that's why I only need
>>>>>standard times (to satisfy ISO Conditions,
>>>>>gamma = 0.8).
>>>>>I hope my english is understandable!
>>>>>Thanks for your answer
>>>>>>From: Sandy King <sanking@CLEMSON.EDU>
>>>>>>Subject: Re: Developping times
>>>>>>Date: Thu, 17 Feb 2005 08:24:58 -0500
>>>>>>For what process are you developing your film?
>>>>>>Sandy King
>>>>>>>Does anyone can recommend developping
>>>>>>>times for Bergger BPF 200 and Ilford FP-4+
>>>>>>>in Pyrocat-HD (Photographers Formulary
>>>>>>>Thanks a lot
>>>>>>>Delphine Chapuis
Received on Fri Mar 4 09:16:43 2005

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