Effect of light on fine art materials

Frank A. Reynolds <fr0c [at] andrew__cmu__edu> wrote:

>...
>I am interest in knowing whether the wattage, or the color
>temperature of a lamp, is the more detrimental factor.  And if
>fluorescent lamps are less harmful than tungsten lamps?  Actually
>we are trying to determine the effect of color scanners on artworks
>and such information would be helpful when considering the light
>sources used in different models....

Most scanners today are using cold cathode lamps.  The article:
Farace, J. "Scanning Devices," in Shutterbug's 1998 Photographic
Buyer's Guide (on newsstand's now and could be ordered from
Shutterbug), pp 97-101, has a very comprehensive list of scanners
which includes the bulb type. Cold cathode lamps are similar to
neon, which is related to fluorescent tubes.

Thomson, G., The Museum Environment, Butterworth-Heinemann, New York
& London, 1994, 2nd edition, pp. 168-174, has data tables and curves
for various incandescent and fluorescent lamps used in museums.

I have not measure UV output from scanner lamps, but intend to do so
at the next Seybold meeting in Boston (3/99).  My results on light
intensity measurements for scanners have been published on-line at:
<URL:http://www.rlg.org/preserv/diginews/diginews2-5.html#technical>

Light Intensity Comparison Chart

    Scanner exposure            0.0000009 to 0.0000386 Mlx-hrs
    Year's worth of sunlight    115 to 290 Mlx-hrs
    Day's worth of sunlight     0.3 to 0.8 Mlx-hrs
    Day on a museum wall        0.0006 Mlx-hrs
    Life of an artwork          4.3 to 10 Mlx-hrs

My findings were that scanner light intensity was very low, even
with the most aggressive modern scanners (Heidelberg Topaz), and
that the UV component would also be very small.

Timothy Vitale
Preservation Associates
831-684-2731

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                  Conservation DistList Instance 12:45
               Distributed: Wednesday, November 18, 1998
                       Message Id: cdl-12-45-001
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