Illustration: Matt Wood

Seldom in history do we have the chance to witness, much less participate in, a new “age of light.” Previous periods have progressed from oil lamps to candles and gas mantles to the first electric lights of the mid-19th century. Terry McGowan, head of the American Lighting Association and formerly the Lighting Research Organization, refers to the advent of light-emitting diodes (LEDs) as the fourth age of electric light evolving from a continuum of incandescence, fluorescence, and high-intensity discharge (HID). With each new age, however, established light sources rarely are displaced completely. Rather, they are diminished and join an active pantheon of lighting, marked by the appearance of the new source and accompanied by societal impact. Yet lighting today often is relegated as a commodity that is far less appreciated, even among architects, than other design elements such as forms and surfaces.

In this new age, LEDs likely will have an impact far beyond use as replacement sources. They elicit excitement and manifest enthusiasm by those outside of the lighting business; LEDs enchant the young as eye-widening color pacifiers, attract teenagers as fashionable adornment, and entice adults who see the potential of “the new new ‘green' thing”—to borrow a phrase from writer Michael Lewis' book about Silicon Valley. Many members of the International Association of Lighting Designers (IALD) say clients, enamored of this new age, frequently request LED lighting for their projects. Subsequently, these designers find themselves talking these folks off the cliff of LED expectation. Was there ever this same sense of excitement around fluorescents or HID? Doubtful. This excitement is the confluence of a genuinely new source and new concepts, coupled with sustainability and energy savings and a dash of hyperbole. But with the emergence of this new form of light, we also see an illumination source in its adolescence.

Unlike traditional sources, which were developed specifically for illumination, LEDs were first used in direct-view applications as power and status indicators including ubiquitous numeric displays, traffic lights, and scoreboards. LEDs have become the pixels of choice. Indirect general illumination using LEDs arrived only in the late 1990s with the advent of the blue LED that completed the triumvirate of red, green, and blue. Following a few years later were white LEDs, which are blue LEDs cloaked in a spectrum-shifting suit of phosphor. These first white sources were weaklings producing a harsh bluish light in a form not well suited to general illumination and, like compact fluorescents, have left a persistent and unwholesome legacy. But unlike fluorescents, LED improvements continue apace. These are, after all, semiconductor devices from an industry that rolls on relentlessly to the metronome of Moore's Law—the long-used adage that the number of transistors on computer chips doubles and redoubles every 24 months. This aggressive pursuit of performance has driven LED developments to the cusp of general illumination. No light in history has come so far, so fast. LEDs must further improve and there is little doubt that this will happen.

MEDIUM AT LARGE The use of LEDs in architectural applications is still tentative, but many installations reveal extraordinary promise. In part this is because LEDs offer a new medium of light and, like most new mediums, it imitates its predecessors by using the same content and the same context. However, thinking about LEDs as simply a replacement for traditional sources is shortsighted and ultimately limiting. New mediums of communication and entertainment take time to develop their own grammar, vocabulary, and form. Early cinema often was films of plays while early TV produced radio plays that could be seen. Lighting is no different. The first uses of LEDs in the 1960s were to replace the small “grain of wheat” incandescent lamps used in indicators, and decades later, having reached illumination levels, LEDs also are proposed as direct replacements.

Marshall McLuhan, the controversial media guru, once said the lightbulb, while a medium, had no content. McLuhan passed away long before LEDs were tenable for lighting, and I suspect he would have rephrased his statement in view of LED applications today. LEDs arranged in low-resolution media façades for architecture certainly has content. Luminous surfaces composed of these sources have content, and the illuminated becomes illuminating. Why light a surface if that surface can become luminous? People already make a living generating such media displays, and the advent of LEDs drives even more possibilities for such types of large-scale communication. From building façades that reveal occupancy through color and dynamics to interior surfaces that react to the presence of a person or object, these emerging applications are not quite indicators or illumination but something altogether different than what has come before.

PROMETHEUS' LIGHT UNBOUND Architectural lighting is beginning to warm to LEDs. There are already numerous installation examples and many notions to explore. The play of light across a surface, such as the sky or water, can be replicated. This includes the atmosphere of moonlight, starlight, and the use of subtle colors rather than circumnavigating a color gamut. Buildings provide a canvas of possibilities when you are offered a palette of infinite variety. The dimension of lighting control has increased both spatially and in time.

Clues to these new architectural, lighting, and spatial directions often are found in the work of artists who explore light—James Turrell, the late Dan Flavin, Leo Villareal, and others. SmithGroup's Northwest Airlines McNamara Terminal at Detroit's Metro Airport (See “Terminal Bliss,” Architectural Lighting Jan/Feb 2003, p. 10–11) and Skidmore Owings Merrill's Condé Nast cafeteria (See “Condé Nast Cafeteria,” Architectural Lighting July/Aug 2008, p. 44–45), embed and imbue the walls and ceilings of the respective spaces, creating atmosphere and drama using only LED sources. Another example is the dramatic dining room of a Mexico City residence with floors as luminous surfaces. Then there is Los Angles–based design firm Electroland's interactive luminous space atop Rockefeller Center in New York City. Some designers take exterior façades to the point of a “Blade Runner” milieu; life imitates art. All of these and many more examples stretch and extend the use of lighting in architectural spaces. Artists, designers, and architects are not bound by convention in illumination and are exploring new applications and creating new content for this light source.

Like any new technology, architects and lighting designers may learn much from an industry and application other than their own. One such example is automotive lighting. Automotive designers have reimagined vehicle design around LED capabilities. LEDs have been used in cars for several years, first as replacement for some indicators such as brake lamps, and more recently as novel forms of branding. Small size, geometry, and high luminance have impacted shape and surface, even style to an extent, as light is deconstructed into smaller pieces that combine to make a consolidated beam.

DIMENSIONAL LIGHT Unlike the ear, which can discriminate between elements of sound, the eye integrates and cannot distinguish the fundamental pieces of the composite whole. When the options are limited to red, green, and blue, which can make a tolerable white upon a white surface, too often the solution is to use those colors or to circumnavigate the boundary of the lighting gamut producing the “color wash” or “chasing rainbow” effects.

As a result, a “Kodachrome” period of architectural light may be upon us, although there are more than a few colors of light and there is an equal infinity of white light and subtler palettes. We now have the capability of replicating sunlight through the passage of the day, and we can create textures, forms, and shapes of light that were never before possible. This includes virtual skylights and windows, and luminous surfaces that are the new stained glass—a glass that is rich and varied not only spatially, but also temporally.