Re: UV Exposure Source details

----- Original Message -----
From: <wrleigh@att.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Thursday, December 18, 2003 11:56 AM
Subject: Re: UV Exposure Source details

> I packed the tubes as close together as the bi-pin
connectors would allow. I
> have a piece of sheet metal behind the bulbs that must be
grounded. It is my
> understanding that the grounded sheet metal (from Home
Depot) is required to
> provide the proper electric potential between the tubes
and the ground to be
> able to start properly. It also serves as a reflector.
>
> One problem that I did have was that at first the bulbs
did not want to all
> consistently light up, so I needed to run my hand over the
bulbs, apparently
> to force that potential. Now that the bulbs have been used
a bit, they all
> start right up.
>
> Basically, I used the directions that I found at
>
> http://www.eepjon.com/ubldit.htm
>
> I found a few other sets of directions on the web, but
these seemed to be the
> most coherent.
>
>
> --
> Bill Leigh
> wrleigh@att.net
> > I am in the process of building a fluorescent tube UV
exposure unit, but
> > would like some advice on a few details. I have found
lots of
> > information out there already, but some of it is
conflicting. One set of
> > plans has mylar reflectors behind the tubes, yet a
different site says
> > that reflectors are a bad idea. The same site has a
commercial lighting
> > grid between the tubes and the exposure plane for
collimation. I also
> > find widely varying distances between the tubes and the
exposure plane.
> > I will not need to access the interior for burning or
dodging (I use
> > digital negs. and do all manipulations in Photoshop
first). So any input
> > and advice would be appreciated.
> >
> > Jack R.
> >

  It may help in starting the lamps to wind a few turns of
thin wire around them and ground it.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com