The visit of a Museum is basically a visual experience. For that experience to happen, light is the key factor that contributes to creating the right atmospheres as well as to rendering the artifacts and exhibitions value. Without light, it would be impossible to enjoy, learn and experience the visit of a Museum.
Curators and designers develop a precise way to show the collections by defining three important factors: the use of spaces –architecture-, the displays and presentation resources –exhibition design- and the measures taken to minimize objects
Starting at the building’s entrance, there is a transition threshold that welcomes visitors into a particular world where they come to “see” what is inside. Along the path through the exhibition halls, the visitor is carried in a way that helps to deliver a message relevant to the collections of each particular case. Light is the catalyst that reveals the contents of this marvelous world of Museums in several different ways: light delivers information, creates impressions, moves the feelings of the observers and let them admire the objects and enjoy the experience.
Ultimately, a visit to a Museum is lasting in our memory thanks to lighting. An artifact that is set in the right ambiance and accentuated with precise lighting brings an endurable image to our brains that lasts for a long time. While the visit of a Museum might take few hours, the memories last for a life time.
Challenges in Museum Lighting
The diversity of needs inside an exhibition hall are sometimes opposite to each other and this factor presents a singular challenge for the lighting design of these kind of spaces.
On one side, most of the artifacts exhibited are light sensitive in one way or another. That means that the energy carried by light has an impact on the basic materials of objects; as such, light might be a deterioration factor for collections.
Secondly, the physical space of the Museum requires different layers of lighting in order to render the architecture as well as to provide visual conditions for security, wayfinding, sign reading, identification and so on.
Finally, the main purpose of lighting is to enhance the perception of the collections and to set them in the right visual conditions for their best possible appreciation.
What is the role of lighting in each one of these situations? A brief review will shed some light on them.
- Preservation: as a potential factor of damage to the collections, light is absorbe by materials and different effects come out of that process. Some of them are fading, color change, humidity migration, disintegration of surfaces, yellowing, and materials weakening.
Visible light as well as infrared and ultraviolet spectral components of light are the cause of negative effects. So, the need to eliminate IR and UV radiation and to control visible light is essential for the preservation of collections.
International recommendations suggest the following maximum light levels on the surface of exhibited objects.
|Materials||recommended light levels in lux|
|Very sensitive to light||silk, paper, biological specimens, old photography, ivory, lace, water colors, feathers||50 lx maximum|
|Medium sensitive to light||wood, fabrics, oil painting, acrylic, plastics, leather, lacquer, recent photography||150 – 200 lx maximum|
- Collections’ Exhibition
Visual perception is interpreted as the capacity of our visual system to acknowledge information by means of the light that gets to our photo sensitive receptors.
In relation to Museums, the interaction of the visitor with the space, artifacts, signals, other people, objects, etc. has important considerations related to his/her visual performance and the ability to develop a series of visual tasks.
Traditionally, light levels are defined accordingly to those visual tasks and they consider the age of the observer, difficulty of the task, time related to its realization, contrast, relationship of ambient vs accent light, and others.
In many cases, the recommended illuminance values are higher than those proposed to keep adequate preservation conditions for the collection.
A brief list of criteria to be used in planning the lighting for display purposes is as follows:
a) Define a balance between ambient light and accent light on artifacts. A recommended relationship of light levels indicates a ratio of 3:1 between the highlighted surface and the immediate surrounding while a ratio of 10:1 related to the larger area seems adequate.
b) Transition zones are necessary to allow visual adaptation when walking through different areas in the Museum. The halls with most sensitive materials, and so with lower lighting levels, should be allocated after the visitor has had time and spaces to adapt; this is particularly important when open areas with daylight contribution are set before the exhibition halls.
Lighting levels from direct sunlight might have values of dozens of thousands of lux while those at the interiors need to be controlled under 300 lux.
c) Another relevant factor to allow a proper visual adaptation is the control of glare which might cause visual impairment. Glare is present in two ways: direct from the light source, especially those that are badly aimed; and indirect as a result of light reflections on bright surfaces.
d) Selecting light sources with CRI – color rendering index, values higher than 90.
e) Selecting light sources with flexible use of accessories like barn doors, filters, louvers and lenses.
f) Selecting light sources for which their beam’s options are also flexible and adaptable to final lighting conditions.
The Vistors’ Experience
It has said many times that light has the potential to tell the story of a place. This metaphor acquires great sense regarding the experience of visiting a Museum.
Beyond the technical recommendations about lighting levels and other photometric factors, it is necessary to have in mind that light will conveys the visitors to discover the place and find how it is, what there is inside, how do the collections look like.
In a great number of cases, visitors have previous information and a virtual image of what they will see. Good lighting must provide a good degree of surprise and magic to the visit, this means that the atmosphere must add character to the exhibition and the accent light must enhance the appreciation of the objects.
Either if it is about art, history, science or other fields of human achievement, Museums are the custodians of the most valuable heritage and for them lighting is the element that facilitates the relationship between the visitor and the collections.
Víctor Palacio is the founder of ideas en luz independent lighting design practice in Mexico City. Victor’s personal philosophy of design consists in creating unique lighting atmospheres to transform spaces in the benefit of people. His work of 19 years in lighting design includes a broad range of projects in the cultural field, museums, residences, corporate, urban and retail projects. In the professional field, Victor has volunteered for the Illuminating Engineering Society – IES and currently is the President Elect of the International Association of Lighting Designers (IALD). He is a frequent lecturer at lighting courses and international Architectural Lighting events.