Lighting for Museums - Learning Objectives

1. What makes good museum lighting?
2. What are design challenges for museum lighting?
   
3. What are the challenges with LED?

Museum Lighting

When lighting museums we need to consider both the visitors and the collections. 
Guests to your museum are there to observe, learn, and enjoy the displays. It is critical to reduce:

• Direct glare - light shining into your eyes from the light source causing the aversion response of squinting or turning away.
• Reflected glare - image of light source reflected  in the glass protecting the work and obscuring visibility.

Good museum lighting protects the collection and the visitors from unwanted glare.

When selecting lighting sources for healthcare, keep in mind, "You cannot see a color unless the wavelength is present in the light source."  We are used to seeing colors in daylight and this is the ultimate light source; however, many museum environments are in basements or other windowless environments, and also, visitors attend events offered after dark.

The bewildering array of light sources and lighting fixture choices is confusing. Understanding how colors appear under different light sources, CRI, CCT, and other metrics for color rendering, and controlling glare are all important lighting challenges. [1]

Museum Lighting Challenges - Protecting the Collection

The best design manages the presentation of daylight and electric lighting, so hat illuminance levers, spectrum, and time are used to minimize damage while providing good viewing conditions for the visitor. [1]

Lighting can produce heat, affect humidity, and can fade or shift colors. Many collections include materials considered vulnerable to degradation. Organic materials, such as wood and baskets, are sensitive to humidity and temperature fluctuations. Textiles are subject to fading and color shift of both natural and synthetic dyes. Paints, inks can crack, fade, and shift their color over time.
There are two factors in measuring museum lighting; intensity of the light and duration of exposure. Limit light exposure by installing occupancy sensors to turn off lights when galleries are empty. Include nighttime security lighting's contribution to total light exposure.
 For known or suspected light-sensitive materials 50 lux (4.65 fc),  for paintings 150 lux (14 fc), and  for work considered stable to light 300 lux (28 fc). Limit UV to 47 microwattts per lumen or lower.

LEDs in Museum Lighting

The way that buildings are designed, constructed and maintained impacts the way we experience the museum collection.

The Getty on Museum Lighting

James Druzik and Stefan Michalski, Guidelines for Selecting Solid-State Lighting for Museums (Los Angeles: Canadian Conservation Institute/Getty Conservation Institute, 2012) http://www.connectingtocollections.org/wp-content/uploads/2011/08/SSL-Guidelines-Ver.-10.0.pdf (accessed 9 November 2016)

GATEWAY Report
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.

http://www.getty.edu/conservation/our_projects/science/lighting/case.html

Van Gouh Fading

Lewis Smith, ‘Will We Have to Look at Sunflowers in the Dark? Scientists Discover Museum Lights Are Damaging Valuable Masterpieces by Van Gogh and Cézanne, Mail Online, January 7, 2013, http://www.dailymail.co.uk/sciencetech/article-2258344/Scientists-discover-LED-lights-damaging-valuable-masterpieces-artists-including-Van-Gogh-C-zanne.html (accessed 9 November 2016).

cf. Letizia Monico et al., ‘Degradation Process of Lead Chromate in Paintings by Vincent van Gogh Studied by Means of Synchrotron X-Ray Spectromicroscopy and Related Methods. 1. Artificially Aged Model Samples’, Analytical Chemistry 83, no. 4 (February 15, 2011): 1214–23 and Manuela Lunz et al., ‘Can LEDs Help with Art Conservation? – Impact of Different Light Spectra on Paint Pigment Degradation’, Studies in Conservation, http://www.tandfonline.com/doi/full/10.1080/00393630.2016.1189997.

Museum Lighting Standards

•  Lighting Guide 8: Lighting for Museums and Art Galleries (London: Society of Light and Lighting, CIBSE, 2015)
• Garry Thomson, The Museum Environment, 2nd ed. (London: Butterworth-Heinemann, 1986)
• CIE 157:2004 Control of Damage to Museum Objects by Optical Radiation (Vienna: Commission Internationale de l’Eclairage, 2004), 157;
• IES RP-30-96 Museum and Art Gallery Lighting: A Recommended Practice (New York: Illuminating Engineering Society of North America, 1996)
• IES Method for Evaluating Light Source Color Rendition – TM-30, Color Metric Task Group of the Illuminating Engineering Society of North America (IES), 2015 https://www.ies.org/store/product/ies-method-for-evaluating-light-source-color-rendition-3368.cfm.

Articles about UV Damage
Sirri Aydinli et al., ‘On the Deterioration of Exhibited Museum Objects by Optical Radiation,’ CIE Technical Collection (Bern: Commission Internationale de l’Eclairage 1990).

 CIE 157:2004 Control of Damage to Museum Objects by Optical Radiation (Bern: Commission Internationale de l’Eclairage 2004 http://www.cie.co.at/index.php?i_ca_id=433).

Herb Stovel, ‘Origins and Influence of the Nara Document on Authenticity,’ Association for Preservation Technology (APT) Bulletin 39, no. 2/3 (2008): 9–17 http://is.muni.cz/el/1423/podzim2013/SOC310/crd/jar/aut/Stovel-Nara-Document-on-Authenticity-APT-2008.pdf (accessed November 9 2016).

Michael P. Royer, ‘Tuning Optical Radiation for Visual and Nonvisual Impact’ (PhD, The Pennsylvania State University, 2011), http://search.proquest.com/docview/888520435/ (accessed 9 November 2016).

2012 N. Miller and S. Rosenfeld, Demonstration of LED Retrofit Lamps at the Smithsonian American Art Museum, Washington, DC.http://www.pnnl.gov/main/publications/external/technical_reports/PNNL-21476.pdf

Perrin, Druzik, and Miller, SSL Adoption by Museums: Survey Results, Analysis, and Recommendations.
https://en.wikipedia.org/w/index.php?title=Luminosity_function&oldid=740914386

2004 Control of Damage to Museum Objects by Optical Radiation.
http://www.cie.co.at/index.php?i_ca_id=433
Part One - Scientific
Part Two - Museum Environment
Part Three - Recommendations

Museum Conservation Societies

The American Institute for Conservation of Historic & Artistic Works (AIC) - www.conservation-us.org/
The Institute of Conservation - icon.org.uk/
American Alliance of Museums - aam-us.org/

Footnotes

1. Tess Perrin, Jim Druzik and Naomi Miller, SSL Adoption by Museums: Survey Results, Analysis, and Recommendations (Richland, Washington: US Department of Energy, 2014) https://energy.gov/sites/prod/files/2015/02/f19/gateway_museums-report_0.pdf
   

Photo Credits

• Photos on this page by Trish Odenthal, all rights reserved.
  
• Van Gogh Sunflowers = Wikipedia
  

Related Topics

Color in Light Sources & LED Comparisons,     Manufacturer's Educational Links,Color in Paint - Why they Fade , Institutions & Research, Lighting for Healthy Buildings