EI of HP5+

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From: Sandy King (sanking@hubcap.clemson.edu)
Date: 07/19/01-08:33:35 PM Z


I agree with you about the low ISO rating of HP5 with PYRO
developers, especially when developed in ABC+ or PYROCAT-HD to a
density range of about 1.6 for alternative processes like carbon or
platinum. In fact, in these conditions I give the film an EI of a
full 400 (or EI of 800 when basing exposure on an incident reading in
the shadows).

Sandy King

>I found the article by chance some while ago - if it's the same - at this
>adress:
>http://www.phototechmag.com/previous-articles/nov99-weese/nov99-weese.htm
>
>It's still there, and I refer to it often - Thanks! - but lately I have a
>doubt about the ISO rating of HP5 in Pyro. Seems to me finally that 200 is
>too low, and I'm tempted to go higher (320?), because the shadow density in
>my negs seems a bit too dense. Easier to do that than double the print
>exposure time for a palladium print?
>
>Anthony
>----- Original Message -----
>From: Sandy King <sanking@hubcap.clemson.edu>
>To: <alt-photo-process-l@sask.usask.ca>
>Sent: Tuesday, July 17, 2001 3:29 PM
>Subject: Re: pyro literature
>
>
>> I would like to thank Judy for the complimentary remarks regarding my
>> article on pyro developers that appeared in Post-Factory #4. Let me
>> also direct your attention to an excellent piece on pyro by Carl
>> Weese that was published in Photo-Techniques just a few months before
>> my piece appeared in PF. I don't have on hand the full bibliographic
>> citation for Carl's article but perhaps someone on the list does?
>> Carl and I shared quite a bit of our research in preparing the two
>> articles so there should be no surprise that we are in general
>> agreement about most matters regarding pyro development.
>>
>>
>> There is, however, one area in which my experience does not match
>> that of Carl's, and that is in the use of ribbed tubes (of the color
>> print development type) with pyro development. I have used these kind
>> of tubes for several years, for developing 7X17 and 12X20 film and
>> have never experienced any uneven development at the point where the
>> ribs touch the film. My technique is very simple. Load the film in
>> the tube, soak in plain water for 5 minutes, then develop for the
>> required time on a rotating motor-base, lifting the tubes off the
>> base every two minutes for about 10 seconds of vertical agitation to
>> avoid bromide drag. Most of my development over the past several
>> years has been with Pyrocat-HD, a pyrocatechin/phenidone developer
>> described in PF #4. However, I have also developed film in the drums
>> with both PMK and ABC+ without, so far as I can determine, any
>> detrimental results.
>>
>> Finally, regarding Pyrocat-HD, I am now recommending the addition of
>> 4g of EDTA per 1000ml of Stock Solution A. This does not impact
>> developing times but with certain water conditions has proven to be
>> *cleaner* acting.
>>
>> Sandy King
>>
>>
>>
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>>
>>
>> >On Mon, 16 Jul 2001, christine wrote:
>> >
>> >> Steve Shapiro wrote:
>> >> > Let me know if anybody wants toknow more about tray development by
>> >> > inspection using pyro.
>> >>
>> >> I do, I do! I am about to embark on a Tech Pan/Pyro combo. I've never
>> >> used either, but both stand out to me as media I would like to try
>> >> from reading about their qualities. ..... I've read the Film
>> >> Developing Cookbook and am about to read The Book of Pyro.
>> >
>> >Christine,
>> >
>> >Among best (I would say THE best, but it might sound immodest) on pyro is
>> >Sandy King's article, "Mystery and Science of Pyro" in Post Factory #4.
>> >This reviews, summarizes and UPDATES usage, by tank, tray, stand, &
>> >densitometer, et al. Sandy's own invention, based on pyrocatechin, "the
>> >other pyro" (he calls it Pyrocat-HD), apparently has enough advantages to
>> >make folks adopt it, tho I don't know about T-Max.
>> >
>> >There's also Stuart Melvin's pyro on lith film and pyro points from
>> >"Skeptics and Believers." Not to mention Liam's Fun & Games With Blue
>> >Toner, Dallas Simpson on toning with tin, Bob Schramm on Daguerreotypy,
> > >just about the entire history and practice of paper negatives & cliche
>> >verre, and the legendary "Gold Flap" from this very list (this last
>> >followed by reports from a couple of folks who did it and lived to tell
>> >the tale, "live, from the gold field"). Plus, believe it or not, lots
>> >more.
>> >
>> >And that's just Issue #3. E-mail me offlist & I'll tell you (and anyone
>> >who asks) how to get it (or for that matter any P-F to date but #1 or
>#2)
>> >for cost of the postage as "free introductory copy."
>> >
>> >cheers,
>> >
>> >Judy
>> >
>> >.................................................................
>> >| Judy Seigel, Editor >
>> >| World Journal of Post-Factory Photography > "HOW-TO and WHY"
>> >| info@post-factory.org >
>> >| <http://rmp.opusis.com/postfactory/postfactory.html>
>> >.................................................................
>>
>>


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