From: MICHAEL STEINLE (mikad@worldnet.att.net)
Date: 06/24/01-08:47:17 AM Z
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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