Lighting Case Studies
By winter 2007, accelerated light exposure experiments conducted side-be-side in two exposure booths—one equipped with UV-filtered MR-16 lamps and the second one fitted with the third version of the UTEP thin-film filters—were demonstrating that several colorants were indeed fading at slower rates, at equal lux levels, under the UTEP filters. These encouraging results along with a field trial that showed that colorful artifacts, not just Old Master drawings, also looked good in filtered light, led to the next logical step, application to a museum or gallery with a diverse collection.
Georgia O'Keeffe Museum
The Georgia O'Keeffe Museum became the first demonstration site for the new filter designs. This museum was selected because it was small but with a diverse enough collection to match the scale of the project. An additional value the GCI could provide to the museum was to carry out extensive microfading assessment on O'Keeffe's extant studio materials and on a few selected watercolors. This would provide the nexus for reviewing their entire exhibition light and loan policies. A successful demonstration at O'Keeffe would be followed by installation in the gallery spaces at the Getty Research Institute and Getty Museum.
In 2011 the J. Paul Getty Museum at the Getty Villa was the site for the exhibition "In Search of Biblical Lands: From Jerusalem to Jordan in Nineteenth-Century Photography". The exhibit lighting designer, Scott Hersey, and Kevin Marshall, Head of Preparations, selected the Cree 12W LED PAR38 2700K lamp (brand name "LRP38") for the exhibition lighting after mockups in a test gallery with similar objects and in collaboration with Jim Druzik, Senior Scientist, the Getty Conservation Institute, and Thomas Kren, acting Associate Director of Collections.
The goal in the lighting selection was to match the color quality of the Museum's standard halogen lamps as closely as possible with no apparent difference between galleries lighted with LEDs and those lighted with halogen. (Both lamp types had a CCT of 2700K–2850K, with a Duv of less than 0.002, indicating they were very close to the black body locus.) The lamps were used in place of (34) Sylvania 60W PAR38 halogen 30° flood lamps, on a one-for-one basis, in three adjacent galleries. Layers of metal screens are typically used for both lamp types to reduce illumination levels to the precise target value on each specific object.
In this gallery space with 34 display lights, the LED replacement lamp compares favorably against the incumbent 60W PAR38 halogen lamp, reducing power use by 83% and recovering the higher initial cost of the LED in year three of operation. In a 10-year life cycle cost analysis, at $0.12/kWh melded electric rate, the total present value (PV) energy savings amount to $4,621, with a total PV life-cycle cost savings of $9,843 including maintenance. Spot-relamping frequency and cost (at $30 per lamp for spot- relamping) are reduced considerably because of the LED's longer expected life.
The museum staff considered the installation a success and has since begun using the LED replacement lamps in other exhibits.
The report on the Getty Villa case study prepared for the U.S. Department of Energy's solid-state lighting GATEWAY demonstration project summarizes some of the research findings on LED replacement lamps from the GCI. Compared to earlier generation LED products, current warm white (2700–3000K) LEDs deliver less of a spike in the short-wavelength (blue) region, resulting in filtered halogen and LED light sources performing similarly in fading tests. On some materials, the LEDs may have slight conservation benefits compared to filtered halogen, but it would take decades for these benefits to become evident. LED light sources are one tool that curators and designers can use to achieve the preservation targets for objects of art.
The report includes further recommended reading for museum lighting issues.
Page updated: November 2012