Re: Phenidone in Pyrocat-HD

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 08:12:27 2005