Greetings:
The American Institute for Conservation presented an excellent two-day
workshop on Exhibition Lighting as part of its annual meeting last month.
The workshop presented a lot of really good information, including
information about compact fluorescents and LEDs.
Stefan Michalski of the Canadian Conservation Institute presented a table
that provided the general characteristics of light sources and compared all
of the sources that are available. With respect to UV emissions, compact
fluorescents will emit between 100 - 150 microwatts/lumen of UV while white
LED (light emitting diodes) emit between 0-75 microwatts/lumen. For compact
fluorescents a custom made filter will be necessary while filters are not
required for LEDs.
Both types of illumination are very useful at short distances such as in
display cases and relamping frequency is relatively low. But there are
drawbacks with both types of lamps: Compact fluorescents are not easily
directed in a sharp beam and although the LEDs can be easily aimed there are
still technical problems that make them a challenge for use in many museums.
These technical problems, cited in Stefan's chart, and discussed in an
excellent presentation by Richard Kerschner, the head of conservation at the
Shelburne Museum in Vermont, include problems with the color rendering index
(CRI) which varies from 70 (fair) for current all white lamps to 90 (good)
for mixed color LEDs (although the white lamps are expected to improve over
the next few years); variable lamp lifetime; a drop of lamp intensity early
in the lifetime of the lamp; and poor color homogeneity of the beam.
Although a good portion of the 2-day workshop was devoted to the technical
issues associated with lighting (energy conservation, applications, etc.)
including potential damage to museum collections, there was a considerable
amount of information presented and discussion about visual perception,
visual noise, viewer needs and expectations, and the aesthetic impact of
lighting.
At this point, I can't remember if the proceedings will be made available
via the web or in other formats. I have a call in to the AIC office to see
if they can provide additional information about dissemination of any or all
of the proceedings. Once I hear, I will post the answer to Museum-L.
Hope this helps.
Wendy
Conservator
Wendy Jessup and Associates, Inc.
Care of Cultural Property
933 N. Kenmore Street, Suite 323
Arlington, VA 22207
(703) 522-2801
Fax: (703) 522-2802
www.collectioncare.com
_____
From: Museum discussion list [mailto:[log in to unmask]] On Behalf
Of Paul Fritz
Sent: Tuesday, May 01, 2007 10:23 AM
Subject: Re: UV light emissions from Compact Fluorescent lights
It is my understanding that fluorescent lamps rely on UV to work, so they
would put out enormous amounts of UV light. That being said, they use
phosphors to convert the UV to visible light, and how much escapes is
something I don't know.
I'd recommend going with LED lighting rather than UV as it can be made UV
neutral and is much more efficient than fluorescent lamps.
--
Paul C. Fritz
Pamplin Historical Park & the National Museum of the Civil War Soldier
6125 Boydton Plank Road
Petersburg, VA 23803
(804) 861-2408 -- Tel
(804) 861-2820 -- fax
Visit us at
www.PamplinPark.org
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