Lighting in an exhibition space is important as it guides the audience through the institution, creating an experience from the moment they enter the space, to the moment they exit. Each room has the ability to tell its own story and create its own journey through the use of light work. There are three main types of lighting used in art institutions, all of which have their benefits and risks. One of these three types of lighting is in the form of infrared (IR). This type of lighting is known for causing chemical changes by ageing the medium of an artwork. The second type of lighting is ultraviolet (UV). This type of lighting has the tendency to cause chemical alterations due to the high temperature.

These changes can appear as discolouration, cracking, oxidation, changes in configuration, and fading.1 While some institutions are still using fixtures that omit IR and UV, there are steps that can be taken in order to minimise the long-term effects of these types of light sources. One of these ways is by installing a UV-absorbing acrylic sheet. An example of this is when museums incorporate a skylight for natural light, a UV-absorbing acrylic sheet must be installed. In doing this, they are saving on electricity, and the amount of time the pieces are exposed is lessened by the natural cycle of the sun. There are different levels of UV-absorbing acrylic sheet that can be used for different materials. A couple of these include UF-4 Plexiglas, which has a low absorption of UV.

Equally important to the Correlated Colour Temperature (CCT) used in the exhibition space is the consideration of lighting effects. How lighting is used has the ability to convey a mood or create a narrative by manipulating its surroundings. To quote Claude Monet, ‘Form only exists through light, and our perception of the world around us is totally dependent on it.’ Museums are able to use light by contrasting it with dark space in order to create a dramatic effect. They can then bring out a specific focal point or draw attention to a specific object. Beam lights and the different angles used also aid in the lighting of different-sized surfaces and how you want the audience to interact with an art piece, or a space.

When using a narrow accent beam of light to highlight a specific piece, the audience is naturally made aware of where their attention should be concentrated. This technique can also be used to draw attention to a key focal point in an artwork. Narrow accent beams also have the ability to add depth to the object. This technique is often used in relation to three-dimensional pieces. When a wide flood beam is used, this creates a lighting that is not as direct at the narrow accent beam, and has a wider spread across a surface area. This gives the audience a less direct awareness of where their attention should be aimed, naturally allowing them more freedom in their gaze. 2 Surfaces also have the ability to be used as a secondary source of light in an exhibition. When directing a light at a white wall, it has the ability to spread its illumination, being stronger in the centre and diffusing as it spreads. Likewise, a mirror or metal can reflect light, while other materials, such as clay or rock, limit the amount of light they share.3

While it can be difficult to manage natural light, it can be a great way to draw emphasis to a surrounding area in a controlled way. It is also an excellent light source that is energy efficient and has many environmentally friendly and economic benefits.4 An example of this is the Pantheon in Rome, which has a spotlight, named the ‘oculus’, at the top of the building's dome. This spotlight creates contrasts through shadows and light, accentuating the decorative walls, ceiling, and floor.5 Another example of this is the Suzhou Museum, designed by I.M. Pei. The ceilings of this museum are made up pieces of wood, that act as blinds. As the sun moves, so do the shadows of the blinds, creating an artistic play of light on the white vacant walls as you walk through the halls of the museum through towards the exhibition rooms (Figure 2).6

Let's now look at whether these applications are being executed on a practical level. A survey conducted in the spring of 2016 involving twelve museum professionals from ten museums and galleries within the United Kingdom took into deliberation the many variables that are put into practice when determining the best lighting solutions. They took into consideration safe lighting, audience experience, and CCT. The participants of this survey were split between smaller galleries and larger museums, all participants working in some capacity with lighting within these institutions. The results of this survey were all conclusive that the professionals all followed the universal lux exposure and UV recommendations. When asked about safety in connection to lighting artworks, the responses were in relation to the lighting falling below the recommended lux exposure time.

On the next level of importance was that UV was either completely excluded or was limited as much as possible. When observing whether CCT recommendations were followed, the majority of the interviewees answered that these were interpreted a bit looser as there was no direction correlation to colour temperature and damages. A majority also admitted that when choosing CCT, generally the light manufacturer's specs were used instead of manually testing, as this saved time and money. There was a general ethical belief that while some played around with CCT specs, it was important to them that a museum be unbiased in how they represent works in their collection. In relation to lighting effects, ‘the opinion was noted that you have to be very clear about what you are doing and why in order to maintain the reputation of the museum as an arena for honest and unbiased representation.’7

It is the museums prerogative to conserve and display works, providing its visitors with entertainment and an educational experience. Lighting is a critical part of guiding guests through museums. Lighting not only creates an experience but also illuminates artworks and tells a story. Lighting can be used to create a mood or set a scene. Unfortunately, lighting also has the ability to damage art, or when not used properly, convey the wrong message or distract from a narrative.

References

1 Marjorie Shelley, The Care and Handling of Art Objects: Practices in the Metropolitan Museum of Art, New York, 2000, 65.
2 Feilo Sylvania, Lighting for Museums and Galleries, 2015, 7-14.
3 Yuri Macêdo, Natural Lighting for Sustainable Design of Art Exhibition Spaces, 2019, 22.
4 Yuri Macêdo, Natural Lighting for Sustainable Design, 27.
5 Britannica, Pantheon | Definition, History, & Facts, 2019.
6 George Zhang, AD Classics: Suzhou Museum / I.M. Pei + Pei Partnership Architects, 2018.
7 Daniel Garside, Katherine Curran, Capucine Korenberg, Lindsay MacDonald, Kees Teunissen, How Is Museum Lighting Selected? An Insight into Current Practice in UK Museums, 2017, 3-5.