From: ken watson (watsok@frii.com)
Date: 06/24/01-01:17:04 PM Z
Mike,
>From using Pyro I agree generally with what you are saying . But then the
question with the gelatin folks is why do they want the stain if it is NOT
associated with the image / silver in the emulsion?. This was my point of
asking the question as I know a lot of folks who do use Pyro are on this
list. I seem to remember there was some discussion about IF the stain was
associated with the image and I think the fact that Pyro stain is not
present in Collodion is a data point that says Pyro is only staining the
gelatin and really has no correlation with the image.
I would like to hear counter discussion as to why this is not good info or
there is something I am overlooking.
..-----Original Message-----
..From: MICHAEL STEINLE [mailto:mikad@worldnet.att.net]
..Sent: Sunday, June 24, 2001 8:47 AM
..To: alt-photo-process-l@skyway.usask.ca
..Subject: Re: Pyro and staining
..
..
..Ken, this is only a guess on my part, but the pyro developer not staining
..your collodion negative is probably due to the fact that the image side of
..dry plates and modern film is composed of a gelatin emulsion. The
..wet plate
..image is not an emulsion but a collodion film that has the silver
..deposited
..on it in a microscopic layer. It seems that the gelatin is a needed
..ingredient to achieve the stain your looking for. You had also
..recently made
..mention of sulfur being needed in a photographic emulsion as
..George Eastman
..had found out with his failed formula. This seems to hold true
..for a gelatin
..emulsion but I doubt it has any value when it comes to wet collodion
..imaging. Just my opinion. It couldn't hurt to experiment other than maybe
..some wasted collodion.
..Mike
..
..----- Original Message -----
..From: "ken watson" <watsok@frii.com>
..To: <alt-photo-process-l@sask.usask.ca>
..Sent: Friday, June 22, 2001 11:15 PM
..Subject: Pyro and staining
..
..
..>
..> I tried developing a collodion negative using pyro, not a gelatin based
..> one. I even tried to "stain" my negative by soaking it in the developer
..> after fixing to try and build up a stain. None occurred.
..>
..> While Pyro helped build density I suspect the staining folks
..talk about is
..> in the gelatin vs being associated with the image "silver".
..>
..> So here is my conjecture.
..> If Pyro staining is associated with the image why does it not stain
..> collodion negatives?
..>
..>
..
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