RE: UV-exposure units/ UV LEDs:diagrams

The idea of using an enlarger for alt process work is very intriguing, and I think that it just might work. The first question that pops into my mind, though, is how the heck do you focus the enlarger? Won't the focus be different at 395 nm than at the wavelength of your 'normal' incandescent or fluorescent light source?

Earl Johnson
Inver Grove Heights, MN

-------------- Original message --------------
From: "andy schmitt" <aschmitt@warwick.net>

> Hey people
> Look what I just found on the web...
> http://johnbokma.com/pet/scorpion/detection-using-uv-leds.html
> andy schmitt
>
> -----Original Message-----
> From: owner-pinhole-discussion@spitbite.org
> [mailto:owner-pinhole-discussion@spitbite.org] On Behalf Of Matti Koskinen
> Sent: Saturday, November 04, 2006 2:05 PM
> To: pinhole-discussion@spitbite.org
> Subject: Re: [pinhole-discussion] UV-exposure units/ UV LEDs: Cyanotype
> fogging problem solving
>
> eric reuben nelson kirjoitti:
> >
> > I have not tried to expose the papers through an enlarger. I would
> > think it is possible if you really have a dry darkroom and a high out
> > put UV light source, uncoated enlarger lenses, and a lot of time.
> >
> > To print in northern wisconsin, I built an exposure unit from (12) 4
> > foot florescent light tube holders and a light switch. I ordered the
> > UV lamps that are not "purple" coated, instead they are like the ones
> > found in a tanning salon. I use contact printing for my work as you
> > have probably guessed. My exposure times with VDB run about 10 minutes
> > time. I use long selves and a face shield while the light is running.
> > You only have one set of eyes and I spent too many hours in the sun
> > already to risk too much extra exposure. You could try a trial
> > membership at a tanning salon and sneak in a few contact frames and a
> > bucket of water. You will find if you live in a large metro area
> > after a government skin cancer report "home tanning beds" sometimes
> > are free and are 6 to 8 feet long!!
> After getting interested in cyanotypes, I built my exposure unit from two
> blended light 100w bulbs. The good thing is, that they don't need ballast,
> they can be directly screwed in an ordinary lamp. The exposing time is of
> course longer, but these lamps don't have the harmful UV-A(or
> B) component, but still enough UV to expose cyanotypes or gum prints.
> >
> > Recently, i have been concentrating on the eccentricities of wet plate
> > collodion. While doing research on the process a fellow wet plate
> > practitioner found on ebay a LED flashlight which emitted UV band
> > light. He was able to expose the wet plate emulsion in near darkness!!
> > When i read that i began to turn over the idea of mounting a series of
> > LED UV bulbs in interior light fixtures for a still life or model.
> >
> > I wonder if it would be possible to wire a group of these UV LED bulbs
> > into an old omega D2 enlarger and let er rip! The LED's wouldn't be as
> > hot as a point source mercury lamp, and a whole lot safer to have
> > running. This type of configuration may allow for enlargements from a
> > negative onto paper as well (I'm just guessing here).
> >
> > Wow this is longer than i intended and hope this is of interest to
> > list. Any thoughts about the LED's would be of interest to me. I enjoy
> > the problem solving nature and the creativity of the pinhole community.
> >
> >
> > Respectfully,
> >
> > eric nelson
> > artist/educator
> > chili, wisconsin, usa
> I've been thinking this too, but not lately, and haven't found these leds
> yet (except by ordering).
>
> best
> -matti
>
> ps. Still searching my film holders.
>
> pps. Thanks Ed for the printing info.
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Received on Sat Nov 4 15:12:21 2006