Thank you, Dr. Cuffe. The photo tech mag article on chromoskedasic printing is
really interesting.
From: pure-silver-bounce@xxxxxxxxxxxxx
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Laurence Cuffe
Sent: Friday, February 24, 2017 11:34 AM
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] Re: photo paper in camera?
On 24 Feb 2017, at 13:17, Margaret H Albertine
<salbert@xxxxxxx<mailto:salbert@xxxxxxx>> wrote:
I use photographic paper in homemade pinhole cameras. Can anyone explain why it
turns colors? My husband has a theory that it’s pollution reacting with the
emulsion. Here’s an example.
Sissy Albertine
<image001.png>
I like the image!
Again my thinking on this is a bit rusty. What we are looking at here is, I
think, colours generated by a process akin to those that are responsible for
the Mie effects (Academic paper here
http://www.dca.iag.usp.br/www/material/akemi/radiacao-I/Mie_Horvath%20(2009).pdf
). In photographic paper we are looking at the effect of a suspension of
conducting particles, however the particles are not necessarily spherical as
Mie had assumed.
These effects are related to those obtained in chromoskedasic printing, of
which more here:
http://phototechmag.com/chromoskedasic-printing-revisited/
I trust this helps,
Best
Dr Laurence Cuffe
From: pure-silver-bounce@xxxxxxxxxxxxx<mailto:pure-silver-bounce@xxxxxxxxxxxxx>
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Laurence Cuffe
Sent: Friday, February 24, 2017 6:25 AM
To: pure-silver@xxxxxxxxxxxxx<mailto:pure-silver@xxxxxxxxxxxxx>
Subject: [pure-silver] Re: photo paper in camera?
One other interesting thing I’ve done, is to put a sheet of photographic paper
in a large format camera, and leave it for an extended period, Hours, Days… and
the paper darkens without development. An attempt to develop the image will
result in a completely blackened sheet of paper, but scanning the image without
development can result in quite a subtle image, often with some lilac or yellow
tones, even though the original paper was BW.
I think the Darkening is the result of what is known as physical development,
but without going back to the literature, I can’t be sure!
Best
Laurence Cuffe
On 24 Feb 2017, at 12:06, Eddy Willems
<eddy@xxxxxxxxxxx<mailto:eddy@xxxxxxxxxxx>> wrote:
normal paper is 6 ISO
Op 24/02/17 om 08:14 schreef Richard Lahrson:
Dana,
What kind of speed? Was the paper VC?
Rich
On Thu, Feb 23, 2017 at 10:24 PM, Dana Myers
<dana.myers@xxxxxxxxx<mailto:dana.myers@xxxxxxxxx>> wrote:
On 2/23/2017 10:21 PM, Richard Lahrson wrote:
Hi everyone!
I was wondering what kind of results one could expect from
shooting photo paper in camera? Is the scale too short to
be useful to scan?
I made several decent contact prints from a paper "neg" in a pinhole camera,
I'm sure I'm not alone. This, of course, suffered from the softening effect
of printing through the paper, which you could surely avoid with scanning,
reversing and inverting the image.
73,
Dana K6JQ
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