From: Phillip Murphy (pmurf@bellsouth.net)
Date: 07/19/03-05:18:58 AM Z
Hello Sandy,
Neutralizing both positive and negatively charged motes and keeping them
from lighting on a large
horizontal surface is nearly impossible outside of a "clean room". One
thing is that the glass itself creates quite
an e-field once you rub it with a cloth when cleaning. To illustrate how
much so: I have a light table at my day
job that is built within a table having two 3-foot fluorescent tubes.
One of the tubes never lights when you turn
the switch 'on'. Simply rubbing the glass with a sheet of paper a couple
of strokes will fire the lamp!
I've noticed commercial static air cleaners for sale by retailers like
Sharper Image and others:
http://www.ionicbreezeairpurifier.com/
These units might help with the volume of motes in a given room
depending on the size of the room.
Traffic through the area, drafts, ceiling type, flooring, clothing, etc.
all contribute their share of "dust".
Although a "clean room" is best, I have managed in the past by taking a
different tack by not trying to
eliminate them at all. The trick is to keep them moving. As long as
the glass is not acting like a magnet,
which is an easy fix with an antistatic liquid. A good fan blowing
across the surface during exposure
keeps the appearance of dust on the final image to a minimum.
Now, to keep them out of drying gelatin sheets! ; )
best regards,
Phillip
btw, the color and effect of the light you describe is very much like
the UV units I use to photograph
stained gels for research purposes. It's probably been covered on the
list many times here but this
type of output can be very damaging to the eyes. I know that you know
this but thought I'd mention
it for others.
Sandy King wrote:
> Recently a friend sent me information about the following site on dust
> and static control.
> http://www.modernsolutionsinc.com/dust/duststa2.html#Anchor-60134This
> got me looking at the dust and static problem in my own printing
> environment. I print with two different light sources: 1) a 1000 watt
> metal halide HID lamp and, 2) a large 48X32" bank of BLB tubes. Both
> are used with vacuum easels and give very good, but slightly
> different, results. However, the BLB set-up is interesting, almost
> weird, because with this light, which is very dark blue/purplish in
> color, every little speck of dust, lint, dirt, skin flakes, hair, etc.
> stand out in a way that is difficult to imagine if you have never
> worked with BLB light. Completely different look from a bank of BL
> tubes I might add. OK, I was really shocked by all the stuff blowing
> around and landing on the glass of the vacuum easel during exposure
> with the BLB lights. I am sure it is happening with the Metal Halide
> unit as well but the color of the light does not reveal it as well.
> So, what I am wondering is this. Is there any kind of electronic
> anti-static device that one can attach to an exposing unit or vacuum
> frame that would reject this trash, rather than attract it as is
> apparently the case. Sandy King
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