bmaxey1@juno.com
Date: 09/24/01-09:14:27 PM Z
Morse Contact Printer: The argon lamps are extremely fast. Richard, have
you actually tried it for Alt work? I will assume you have, but not sure.
Remember, the light from an argon source is different than light from a
strong UV source. You have a great printer, by the way.
I have found the biggest problem with those lamps, is that with some
modern papers, I can't prevent overexposure. Can't flip the switch on and
off fast enough, so I had to modify mine. For example, Resin Coated
Kodabrome was a real bear to print because it would easily overexpose.
When you could obtain it cheaply, I used flashed opal glass as a blocker.
I also used graphite and tissue to dodge with, and typically, I would use
AZO paper because of its speed. Argon is very fast.
Before someone asks, trying to speed up ALT work, argon is of little use
because it is extremely expensive to obtain the lamps that are suitable.
FYI: I changed each on-off switch to a rheostat and this adds even more
control.
GLASS: There are hundreds of types out there. If there is interest, I'll
post links. Quartz was mentioned. Yes, but expensive as heck to obtain.
The color of the glass has little effect in my experience. When I broke
mine, I replaced it with a sheet from the hardware store. I noticed
little changes.
Mine, too has a green tint to it. the actual amount of UV passed or not
passed is impossible to judge accurately - IE, specific amounts as
percentages, without a meter that measures UV. In my opinion, this can't
be accurately judged if the user is mixing emulsions because of
variations.
There are glasses termed UV Clear, but this is not an accurate definition
as all manufacturers judge this on their own. A supplier who
manufacturers specialty glass for lab use, filter manufacturing and other
specific applications can give you more specific info. Tons of references
such as F.W. Grey will be of help. They carry a vast amount of types and
can custom formulate, but that is overkill I think.
Personally, I am not too sure if it is a worry or bother. Remember, print
frames have been made from decades, and the type of glass most used was
most likely an inexpensive type.
FRAMES: Someone mentioned how to check exposure. With my frames, the
backs are covered with felt and hinged so each side can be independently
opened. If you are careful, you can judge progress quite easily.
Good Luck
HCM
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