Re: Phenidone in Pyrocat-HD

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
solution.

Sandy

>Sandy,
>
>And what was the result with Pyrocatechine only?
>
>Delphine
>
>>From: Sandy King <sanking@clemson.edu>
>>Reply-To: alt-photo-process-l@sask.usask.ca
>>To: alt-photo-process-l@sask.usask.ca
>>Subject: Re: Phenidone in Pyrocat-HD
>>Date: Fri, 04 Mar 2005 09:12:13 -0500
>>
>>Delphine,
>>
>>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.
>>
>>Sandy
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>>Sandy,
>>>
>>>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>
>>>>Reply-To: alt-photo-process-l@sask.usask.ca
>>>>To: alt-photo-process-l@sask.usask.ca
>>>>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
>>>>http://unblinkingeye.com/Articles/PCat/pcat.html
>>>>
>>>>This article was translated into French as
>>>>"Introduction aux révélateurs colorants au
>>>>pyro" and is in the French language site
>>>>Galerie-Photo, at
>>>>http://www.galerie-photo.com/revelateurs-colorants-au-pyro.html.
>>>>
>>>>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.
>>>>
>>>>Sandy
>>>>
>>>>
>>>>>Sandy,
>>>>>
>>>>>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
>>>>>process.
>>>>>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
>>>>>
>>>>>Delphine
>>>>>
>>>>>>From: Sandy King <sanking@CLEMSON.EDU>
>>>>>>Reply-To: alt-photo-process-l@sask.usask.ca
>>>>>>To: alt-photo-process-l@sask.usask.ca
>>>>>>Subject: Re: Developping times
>>>>>>Date: Thu, 17 Feb 2005 08:24:58 -0500
>>>>>>
>>>>>>For what process are you developing your film?
>>>>>>
>>>>>>Sandy King
>>>>>>
>>>>>>>Hi,
>>>>>>>
>>>>>>>Does anyone can recommend developping
>>>>>>>times for Bergger BPF 200 and Ilford FP-4+
>>>>>>>in Pyrocat-HD (Photographers Formulary
>>>>>>>formula)?
>>>>>>>Thanks a lot
>>>>>>>
>>>>>>>Delphine Chapuis
Received on Fri Mar 4 09:16:43 2005