Re: some observations (and a question) regarding using the sun as a light source

That might have been me, Judy, as (now devoid of an educational institution
and a fab light box) I have been doing all my alt. proc. work in the sun -
all year round too. I was surprised that exposures could be so short in the
sun for gum, and about 8 years ago that was certainly the case as I was
making both big and little gums in the sun. This is Aussie sun I'm talking
about here, and, at the risk of this comment being seen for what it is, the
sun is MUCH more 'active' now than it was even 20 years ago from my printing
experience. I think it was Kate who noted recently that the ozone hole above
NZ (and Tasmaina too I understand) is a big one.

More recently, I have been making cyanotypes as photograms (no film) and
these are a little more flexible time-wise. Again only minutes produces an
image, but intensive work on the objects in the sun means I have been
exposing for up to 45 minutes Double printing worked better than I expected
too - it didn't fade as I expected. But I hardly dare check to see in case
they have.

Catherine

----- Original Message -----
From: "Judy Seigel"

> On Sat, 7 Aug 2004, Keith Gerling wrote:
> > I was astonished to learn just how bright the sun actually is! Six
minutes
> > under my fluorescent bulbs equals three minutes under my Violux equals
about
> > 45 seconds under the noonday sun. But the time of day causes very
extreme
> > variances in the amount of light. A minute at noon might be 4 minutes
at
> > 3:00 PM.
>
>
> In the early days of the list, a woman whose name I'm not remembering now
> said she exposed gum by sunlight -- & that at noon in summer the exposure
> was 30 seconds.
>
> Some of the old British Journals of Photography have exposure charts by
> season and latitude -- and as I seem to recall, maybe Henney & Dudley have
> one too. But of course you'd have to factor in your medium...
>
> Judy
>
Received on Mon Aug 9 12:05:17 2004