From: Liam Lawless (liam.lawless@blueyonder.co.uk)
Date: 03/04/03-10:52:47 PM Z
John,
Yes, sure you'd get a stain along with the developed silver, but it'd still
be a thin neg. (C41 films don't contain a lot of silver, so there'd be
correspondingly low staining.) Colour couplers are used in chromogenic
toning (where they're properly known as colour formers); maybe modern C41
films use different couplers, but some of the ones I've used in toning are
alpha-naphthol (blue), 2-4-dichloro-1-naphthol (cyan), nitrobenzyl cyanide
(magenta) and acetoacet-o-chloranilide (yellow). Don't know the chemical
formula of pyro stain (is it in Hutchings?) or of the dyes that are produced
in C41, but the colour coupler formulae don't look anything like that of
pyro.
Maybe you should ask Richard :)
Liam
-----Original Message-----
From: John Campbell [mailto:tojohn@texas.net]
Sent: 05 March 2003 04:43
To: alt-photo-process-l@sask.usask.ca
Subject: Re: C-41 in b&w chemistry
Greetings, all--
Okay, I'm gonna pitch in here, even though it's a bit premature.
Over a year ago (if memory serves me) I accidentally loaded (meaning I paid
no particular attention) and developed several rolls of B/W C-41 along with
several batches of TMX and developed the lot via Pyro. I recall being
mortified/curious/delighted with the results. I edited and printed several
of the C-41-Pyro's and thought they were quite nice. Then I dismissed the
whole affair as anomaly and went back to paying attention.
. . . until this thread came up.
And since this thread came up (and reminded me of events from over a year
ago), I've been searching (or intending to search) for those C-14-Pyro
negatives.
(I'm sure I have them somewhere. . . . )
In the meantime, my question for Liam is: Might Pyro stains take the place
of the C-41 color dyes? (. . . and might they be related, chemically?)
. . . and my question for Keith is: Why do you ask?
With delight,
John
www.photogekco.com
----- Original Message -----
From: "Liam Lawless" <liam.lawless@blueyonder.co.uk>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Tuesday, March 04, 2003 4:26 PM
Subject: RE: C-41 in b&w chemistry
> Keith,
>
> The C-41 emulsion contains three layers of silver halides and colour
> couplers. Oxidation by-products of silver development combine with the
> couplers to form the C, M and Y dyes, after which the silver (thinner than
> in B&W film) is no longer needed and is bleach-fixed away to leave just
the
> three dye images. Or something like that.
>
> With a straight b&w developer, the coloured dyes do not form and you end
up
> with just a thinnish silver image. Plus, I think I read somewhere, the
> unused couplers contained in oily globules, which I believe can be removed
> (with alcohol, perhaps?)
>
>
> Liam
> -----Original Message-----
> From: Keith Gerling [mailto:keithgerling@att.net]
> Sent: 04 March 2003 19:06
> To: alt-photo-process-l@sask.usask.ca
> Subject: OT: C-41 in b&w chemistry
>
>
> Can anyone here explain what would happen if C-41 film happened to be
> processed in chemistry intended for black and white film?
>
> (no, I didn't actually DO this. Just curious)
>
> Thanks!
>
>
>
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