Re: making regular photo paper POP

Thanks everybody for chipping in. Ryuji, what do you think that potassium
thiocyanate will do? I am going to try it anyways. I have coated some
dilute silver nitrate on the papers to get stronger POP (and different
silver grains). Got to go check on my exposures.
Marek

> 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 13:04:30 2005