Re: point source UV?


Greg Schmitz (gws1@columbia.edu)
Mon, 22 Nov 1999 23:01:52 -0500 (EST)


Joe,

With regards to the spectral sensitivity of gum, my suspicion is that
it is not written in stone. Possible variables would include, the
gum, the pigment mixed with the gum, other chemical constituents of
the emulsion or in contact with the emulsion, the age of the emulsion
and perhaps the pH of your water supply and even the paper the emulsion
is coated on (and perhaps how long the emulsion has been on the paper)
- deep breath :*). You might want to take a look at Jaromir Kosar's
book (listed below) for more information, though the book will not
provide you with any specifics of the "use this this way" variety but
rather some things to think about and/or perhaps test. I know Kosar's
book has been mentioned on this list before.

As for cheap light sources, this topic has been discussed here in
ALT-PHOTO before and I know it has been discussed on the LETPRESS list
(which is archived somewhere in hyperspace). Some folks have
successfully used metal-halide street lamps for UV sensitive
materials. These are probably only "cheap" if you can find a used
one, perhaps when a building is torn down or a parking lot revamped
(creative searching is the key). In most cases the nominal
specifications for commercial light sources are available from the
lamp manufacturer.

            AUTHOR: Kosar, Jaromir.
             TITLE: Light-sensitive systems : chemistry and application of
                    nonsilver halide photographic processes / Jaromir Kosar.
         PUBLISHED: New York : Wiley, 1965.
  PHYSICAL DETAILS: xv, 473 p. : ill. ; 24 cm.
            SERIES: Wiley series on photographic science and technology and the
                    graphic arts.

          SUBJECTS: Photography--Printing processes.
                    Photographic chemistry.

             NOTES: Includes bibliographical references and index.

              LCCN: 65-22427

-greg schmitz <gws1@columbia.edu>

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Hope for the best, but be prepared for the worst.

                        US ARMY SURVIVAL MANUAL

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