Show true colours with LED lighting
LED lighting has emerged as a versatile technology for museum and gallery applications, able to showcase art in its true light while delivering significant energy savings.
Earlier this year, The Smithsonian American Art Museum in Washington DC, organised a conference on the specific topic of LED lighting in museums and galleries. Confirming wide interest, the event was a sell-out as a mix of 300 curators, conservationists and lighting designers gathered valuable advice from some of the early adopters of the technology.
Today’s LED technology offers far higher levels of brightness and energy efficiency than seemed possible just a few years ago. And that is part of the challenge – even for an experienced designer, the wealth of LED lighting options now available might seem overwhelming.
The decision to invest in a new or different lighting technology is not only of huge importance to curators and designers. Because of the energy- and cost-saving potential of LEDs, facility managers are taking such matters very seriously too.
LED lighting experts agree that it is difficult to find a lighting application with aesthetic standards higher than those of museums. Colour, intensity, beam angle and light distribution must all be given due consideration. With the ever-wider variety of LED options becoming available, selecting the best source is not getting any easier. Here are five tips to help make that choice:
1: Low intensity:
LED lighting might have made giant strides in terms of brightness over the past few years, but that is not necessarily what a museum or gallery needs – particularly when it comes to delicate works that need to be protected from thermal damage. But one of the key benefits of good LED lighting is that it delivers only visible light, cutting out the damaging ultraviolet and infrared elements.
In his Smithsonian presentation, the American Art Museum’s lighting designer Scott Rosenfeld said that the intensity of lighting in museums was determined by the specific need for conservation of each artefact in question – and that only the lowest light levels necessary should be used.
The most sensitive artefacts in a museum would typically be limited to an illuminance of just 50 lux, and Rosenfeld warns that LED sources with a correlated colour temperature (CCT) in excess of 4000K are more likely to be damaging. His top tip: “Turning the lights off when people are not in the room is the best thing we can do to save energy and save our collections.”
2. Bring out true colours
Displaying art in the form intended by its creator is the ultimate aim of the gallery lighting designer, but is harder than it sounds. Daylight might be good for showing the true colours of an oil painting, but that same daylight would also be highly damaging in the long term. LED lamps allow designers to select a CCT level that best matches each artwork. At the Smithsonian, curators found that changing CCT from 2700K to 3000K made blue tones, such as painted skies, more vivid.
Bringing out that “true colour” depends upon both the chromaticity of the source and its colour rendering index (CRI). Verbatim’s “Vivid Vision” directional LED lamps tap into this need and are designed to meet the specific requirements of museum exhibits. Using proprietary VxRGB technology developed by Verbatim’s parent company, Mitsubishi Chemical Corporation, Vivid Vision ensures that colours and fine details of objects are rendered accurately. Such high contrast lighting is being deployed to bring out the subtle differences in colours, hues, tints and textures of artworks.
3: Beam angle
Much like theatrical lighting, exhibit illumination in museums in focused on its primary subjects and the availability of lamps with different beam angles represents one of the key elements of control for a designer.
For a given beam angle, LED lighting tends to offer a greater intensity in the centre of the beam profile. And while the combination of a small filament and precise optics in halogen lamps means that they are good for very tight “spotlight” distribution on small artworks, LEDs featuring a wider beam angle can also be advantageous.
At the Brooker Gallery in Chicago’s Field Museum, for example, curators were able to replace 32 halogen lamps with just 26 LED luminaires giving an equivalent spread of light. Verbatim’s MR16 20W halogen replacement, rated at 6.5W, produces 180 lumens over a 55 degree beam angle.
4: Set up a test
Because of the specific nature of individual museum and gallery requirements and the wealth of LED lighting options, a large museum will likely need different sources for different exhibits and rooms.
Of course, there is no substitute for a practical evaluation of LED lamps rather than relying on the performance claims of data sheets. Experts recommend mocking up light sources with similar light levels, similar paint finishes and on similar artwork in a test gallery first.
Rosenfeld adds that all lamps considered for US museums should offer an “LM-79” quality report and detailed spectral power distribution (SPD) data. He also recommends that designers acquire a spectrometer so that key metrics can be checked out in situ.
5: Intelligent distribution
It isn’t just about the total lighting intensity. In a nutshell: put the light where you want it, and take it away where you don’t. Making each work of art stand out in a room that could also feature competing general lighting and daylight is best achieved by carefully matching the spread of the illumination to the size of the target piece.
That approach also cuts out unwanted shadows and light spill, while glare can be reduced by pushing lenses further back in the luminaire. But watch out for ugly “scallop” shaped spots on the wall behind an illuminated piece – these result from circular lenses, and switching to asymmetric optics offers a solution.
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In addition, the company is an innovator in fast-growing LED and OLED lighting, developing products that offer low power consumption, long life and a better lighting experience. It is also an emerging supplier of water filtration systems; its Cleansui brand is Japan’s favourite water filter.
Verbatim is a subsidiary of Mitsubishi Kagaku Media owned by Mitsubishi Chemical Corporation, one of the world’s largest chemical companies, which invests heavily in R&D across many diverse sectors. The company’s operating principles are founded on helping people to live in a healthy, comfortable and sustainable way. Verbatim’s regional organisations are EMEA, APAC and Americas, with offices in most countries in the world. The company’s European headquarters are based in the UK. For further information, visit http://www.verbatim.com