Re: Anyone doing autochrome?
Barry,
I had the joy of being in the bromoil class with a chemist physician who
practiced whatever that field of medicine is where they determine risk and
safety stuff at large corps. Anyway, he was a wealth of photo lore. One
thing he told me was that the slime goop that kids play with is none other
than gum arabic (or even PVA in some cases) mixed with boric acid. Boric
acid makes gum go instantly hard (gum viagra?). Jim suggested using this as
a sizing. Coat the paper with gum and then harden it in a 1-2% boric acid
bath. As a person offlist reminded me, though, when I added acids to my gum
mix I got more and more staining/non-exposure hardening in my gum layer as
per the example on my website in the learning section on gum, so it may be
an iffy proposition. I wonder if the residual boric acid would then affect
subsequent gum layers, making it unsuitable for gum, but certainly this was
a less toxic form of sizing to dink around with.
But ANYWAY, is it possible to do some sort of boric acid/gum thing with your
class and allow them to make goo to play with? What is it called, GAK?
Then, this guy also did a copper sulfate print which was really quite
beautiful, reminiscent of Bernie Bertridge's cupric print at APIS. I think
it might have been Obernetter's formula, or something he devised himself.
So that could be done in tandem with a cyanotype demo--a pink print and a
blue print. And copper sulfate is cheap. If you want, I could email him
and ask his formula.
Chris
----- Original Message -----
From: "Barry Kleider" <bkleider@sihope.com>
To: <rvallon@cox.net>; <alt-photo-process-l@usask.ca>
Sent: Wednesday, August 29, 2007 7:52 AM
Subject: Re: Anyone doing autochrome?
Hi, Richard,
Thanks for writing.
I've seen enough autochromes to know what I'm looking at, but I can't say
know much about the autochrome process -- except that it produces a color
image using potato grains on a B&W base emulsion. I know the originals
were done on glass plates. I accept that we don't have a multi-ton press
in a light-tight room to make the real thing. Even if the images were a
bit fuzzy, less than permanent, could the process be done on B&W sheet
film?
My interest in asking is that I work with high-school students in an
arts-infused program. This means we use the arts to teach other
ubjects -- chemistry in this case. For the past two years I've been doing
cyanotype printing with a group of chemistry students as a way of teaching
about chemical reactions. I'm hoping to deepen my bag of tricks as it
were. So, I'm not looking for a digital rendition, but an actual
physical/chemical process. (In the best of all possible worlds, I could
wow my students by showing them photos made from a potato.)
BTW, the idea of doing autochromes was only one thought. I'd entertain any
other ideas for other darkroom chemistry projects. Keep in mind these are
high school students. Anything involving critical measurement of hazardous
chemicals probably wouldn't look too great on the evening news.
Barry
Richard Vallon Jr. wrote:
On Aug 28, 2007, at 1:58 PM, Barry Kleider wrote:
Is there anyone on the list with experience doing autochrome printing?
I'd like to do some experiments on my own and then offer it to some of
my high school students.
Barry Kleider
Hi Barry-
Are you familiar with this process? I'm asking as it is a glass plate
covered with colored potato starch grains.
The grains are pressed together under a multi ton press then the back of
these grains is coated with a photo emulsion
- this plate is then developed as a positive after it has been exposed
in camera...
The final result is a color transparency...
So the chances of anyone doing this themself w/o a research grant are
small.
However- it would not be impossible to contact print onto color photo
paper through a multi colored screen made in an inkjet printer.
I also have a simple digital method in photoshop that looks very similar
to an autochrome.
If this interests anyone I can write this up...
Richard Vallon - Orleans Photo Inc.