Re: making regular photo paper POP

From: "Christina Z. Anderson" <zphoto@montana.net>
Subject: Re: making regular photo paper POP
Date: Thu, 01 Sep 2005 19:06:00 -0600

> First, he exposes for anywhere from 15 minutes to several hours, but
> he seems to mention the several hour bit the most. In the hot
> equatorial sun, mind you! Direct. On the top of his boat. Under
> glass or not under glass, taped down or not taped down. In rain or
> not.

Commercial b&w papers are designed for developing process, of
course. Favorable conditions for POP differ drastically from those for
DOP, so his choice of much longer exposures to make POP's from DOP
papers doesn't surprise me much.

> Now, where he and I differ in process is this: I have never just left an
> exposed print for a period of time before fixing. That could have some sort
> of effect (continuing action, perhaps??)

If the paper exposed for hours is kept in dark, I do not expect
significant degree of change occuring during the dark storage. If
there is some overall light exposure during the storage (or before
exposure), it's a different issue. Silver gelatin process in usual
conditions doesn't have dark reactions like in dichromated colloid
processes.

> This student will be working on this all semester and I will report back
> more results. What I am going to suggest she do is use some Kodak S2 and
> S30, if it is still available (I have a quart of both) and sprinkle it on
> here and there. That is what I use when I teach chromoskedasic sabattier in
> the darkroom, and it produces beautiful color as Ryuji was explaining, by
> the Mie thingy. I'm so scientific...Don't ask me how, I'm just going to
> wing it.

Did you try some plain NaOH (or KOH) and potassium thiocyanate to
substitute for S2 and S30?

Ryuji
Received on Fri Sep 2 00:29:55 2005