Led Lights
LED LIGHTS
A Museum Exhibit Case Study
By Kathy Andal
September 6, 2013
In April 2014, the Durango County Museum of History installed a small exhibit titled Our heritage: Pictures from the past. The collection consists of five daguerreotypes and several silver albumen prints. A study was made to measure the benefits and costs of using LED. lights instead of traditional halogen lamps.
RISKS OF LIGHTING HISTORIC PHOTOGRAPHS
All lighting harms photographs. (Lavedrine 2003) It is the task of the conservator to minimize this harm so that the photographs can be viewed for a significant span of time, typically 50 to 100 years. For these reasons, historical photographs are displayed only periodically in rooms with significantly reduced lighting. These practices minimize the visitor experience and according to Hunt, reducing light levels diminishes color saturation and contrast. (Hunt 1952, 192)
In all lighting systems, ultraviolet light (UV) must be eliminated as that spectrum harms photographs the most. Halogen lights must have UV filters installed which adds to their cost and effectiveness. LED. lamps do not emit UV light and do not need extra filters. According to a study by the Getty Conservation Institute, fading from LED. lamps does not result in any more damage than conventional halogen lamps with ultraviolet filtering. They found that it is likely using LED. lamps results in less fading of photographic materials. (Druzik and Miller 2011)
METHODOLOGY
In the new exhibit, 12 watt PAR38 20° lamps were utilized. The temperature rating for these lamps was 2700 Kelvin. Although the LED. light output was significantly less than traditional halogen lamps, some screening was still needed. UV filters were not installed because LED lights do not emit any significant levels of ultra-violet light. This simplified the installation process.
In the past, the museum curator would have lighted the exhibit with 60 watt, PAR38 30° 120V halogen flood lamps. UV filters were
A Museum Exhibit Case Study
By Kathy Andal
September 6, 2013
In April 2014, the Durango County Museum of History installed a small exhibit titled Our heritage: Pictures from the past. The collection consists of five daguerreotypes and several silver albumen prints. A study was made to measure the benefits and costs of using LED. lights instead of traditional halogen lamps.
RISKS OF LIGHTING HISTORIC PHOTOGRAPHS
All lighting harms photographs. (Lavedrine 2003) It is the task of the conservator to minimize this harm so that the photographs can be viewed for a significant span of time, typically 50 to 100 years. For these reasons, historical photographs are displayed only periodically in rooms with significantly reduced lighting. These practices minimize the visitor experience and according to Hunt, reducing light levels diminishes color saturation and contrast. (Hunt 1952, 192)
In all lighting systems, ultraviolet light (UV) must be eliminated as that spectrum harms photographs the most. Halogen lights must have UV filters installed which adds to their cost and effectiveness. LED. lamps do not emit UV light and do not need extra filters. According to a study by the Getty Conservation Institute, fading from LED. lamps does not result in any more damage than conventional halogen lamps with ultraviolet filtering. They found that it is likely using LED. lamps results in less fading of photographic materials. (Druzik and Miller 2011)
METHODOLOGY
In the new exhibit, 12 watt PAR38 20° lamps were utilized. The temperature rating for these lamps was 2700 Kelvin. Although the LED. light output was significantly less than traditional halogen lamps, some screening was still needed. UV filters were not installed because LED lights do not emit any significant levels of ultra-violet light. This simplified the installation process.
In the past, the museum curator would have lighted the exhibit with 60 watt, PAR38 30° 120V halogen flood lamps. UV filters were
Bibliography: Druzik, Jim, and Naomi Miller. Guidelines for Selecting Solid State Lighting for Museums. 2011. http://www.getty.edu/conservation/our_projects/science/lighting/lighting_component8.html (accessed April 13, 2014). Hunt, Robert W. "Light and Dark Adaptation and Perception of Color." Journal of the Optical Society of America , 1952: 190-199. Lavedrine, Bertrand. A Guide to the Preventive Conservation of Photograph Collections. Los Angeles: Getty Conservation Institute, 2003. Wiggens, Matthew, Kurtis McKenney, John Dieckmann, and James Brodrick. "Solid-State Lighting, Part 2: Applications." ASHRAE Journal (American Society of Heating, Refrigeration and Air Conditioning Engineers, Inc.) 52, no. 2 (2010): 78,80-81. -------------------------------------------- [ 1 ]. Screening is the process of installing layers of metal window screen. [ 2 ]. A blended electricity rate was used. This averages time-of-use, demand charges, and fees. [ 3 ]. Derived from industry standards.