I was a very different person two years ago. Until then, I had spent most of my life designing the lighting for theatrical productions, and architectural projects encompassing mostly hospitality or cultural facilities: restaurants, resorts, spas, and museums. But two years ago I took a different position with a new firm, and my area of concentration shifted to predominantly site and landscape lighting design. With more than 25 active design projects spanning the state of California, including retail centers, apartment communities, and corporate and college campuses, I now spend an inordinate amount of time outdoors after dark evaluating the man-made nighttime environment. And, in the process, I have found myself bumping into a few potentially dangerous things in the night: municipal lighting codes in large urban areas such as San Diego and San Jose that bow to the needs of astronomers; the LEED credit SS8, which provides for extremely limited uplight and light trespass; and the evolution of the Model Lighting Ordinance (MLO), a joint venture between the International Dark-Sky Association (IDA) and the Illuminating Engineering Society (IES), which proposes strict limitations on exterior lighting.
I have found myself immersed in "political correctness" as it pertains to our lit environment. Although there is a lot that is on target regarding Dark-Sky issues, I have learned that there is just as much that is obsolete, or is poorly developed thinking that is being embraced as gospel. Before it is too late, and new ordinances are adopted without fully understanding their impact, those of us who are lighting designers need to become more actively engaged in the debate of what makes a quality nighttime environment, and help provide balance to the discussion.
The IDA is composed predominantly of astronomers, but does count some lighting designers and illuminating engineers as members, and has become the prominent voice in the debate over how our world should, or should not, be lit. The IDA pronounces a fundamental human need to see the stars, and demands legislation to ensure that these needs are preserved in the face of human development.
As someone who has spent a lifetime in the theatre contemplating the mysteries of the human condition, I am more and more unsettled by what they propose, because there seems to be little recognition of something else deep and fundamental to the human soul-its response to, and need for, light. But not just any light, I mean celebratory, uplifting, and inspiring light.
Human beings have been sitting at firesides for hundreds of thousands of years, and this has hardwired our brains and our souls profoundly. For all those millennia, as the natural light of day, where bright, cool-white light from above provides us with the energy to see, moved to night, our relationship to our lit environment shifted to dim cool light from above-moonlight-and warm man-made light from below, firelight. Human beings not only see, but also feel, light in certain ways. Only when Thomas Edison invented the electric light bulb 130 years ago did human beings begin to experience an inversion of this evolution-warm light finally came from above, and could be placed at greater than arm's length to replace the moon.
Studies by neuroscientists, such as Eve Edelstein, who holds degrees in Architecture, Anthropology, and a doctorate in Neuroscience, have shown that under cool-white light our eyes not only see better as a result of a wider spectral bandwidth, but our brains function better, processing information more quickly. I believe this has a correlation to the activities in which humans have engaged for hundreds of thousands of years under those cool-white light conditions: hunting during the day and avoiding being hunted at night, activities that demanded alertness and higher brain functions to survive.
I think about these things as I drive down the freeway in San Diego at 70 miles per hour under the low-pressure sodium lights that nearby astronomers have advocated for years. Wouldn't I be more alert if those lights were cool-white, instead? Wouldn't I be safer?
Low-pressure sodium (LPS) is the favorite light source of astronomers and the IDA. They are very clear about this on the IDA website, and both the Lick Observatory in San Jose and the Mount Palomar Observatory near San Diego urge their communities to continue the use of LPS. The extremely narrow spectral bandwidth of LPS allows astronomers to "tune out" this lighting interference as they gaze skywards. Thirty years ago, when the City of San Jose adopted LPS over other sources, the claims of the astronomers at Lick that LPS was the most efficient light source available was true-on paper-and was a potent argument for the otherwise problematic light that LPS provided those of us living beneath it.
What must be contested now is that this is still true. Many municipalities are investigating new technologies for lighting their streets, but encounter, if not hostility to the idea, then a lack of support or facts from the IDA and from many astronomers. From the Mount Palomar website under "Why Astronomers Love Low Pressure Sodium" it states, "The energy savings [of LED] question is a bit muddled though. Low-pressure sodium is still the most efficient lighting source around. It is about three times more efficient than the best LED lights around these days." This is simply not true, and hasn't been for a while. Although simple math shows a very high lumen-per-watt ratio of LPS, studies into scotopic and photopic ratios at the Lawrence Berkeley National Laboratory (LBNL) reveal that the human eye, and brain, operates differently.
Under limited spectral bandwidth, the human eye does not see very well. For us to see and function optimally, especially as we now move through the world at speeds that were unimaginable even a century ago and require rapid visual recognition, we demand a full spectrum of light. Recent studies in Anchorage, San Diego, and San Jose conducted by Boulder, Colo.-based Clanton and Associates in association with the Virginia Tech Transportation Institute have shown conclusively that visibility and safety are increased, with energy reductions of up to 40 percent, using light sources with wider spectral bandwidth. The wider the spectral bandwidth and the higher the color temperature, or the closer the color of the light comes to daylight (or moonlight), the less of this kind of light we need to see better. LBNL has developed a chart to help understand this correlation. For example, a 180W LPS which provides 22,400 mean lumens for a seemingly impressive 124 lumens-per-watt ratio, when adjusted for its color rendering index (CRI) and its ballast factor, really provides only four visually effective lumens per watt, lumens that really matter to our eyes and brains. A 70W T6 metal halide source with a CRI of 75 and a color temperature of 4000K, although initially providing a less exciting lumens-per-watt ratio of 31, when adjusted for its visual effectiveness, outperforms the LPS source dramatically at 46 visually effective lumens per watt, or more than 10 times better at almost one-third of the power consumption.
But efficiency isn't just about photopic and scotopic ratios relative to lumen output; it's also about applying them to the task properly. If your lumen package is really just a ball of light, which has minimal optical efficiency (a long tube of light, in the case of LPS), it is wasting a large percentage of its light output when attempting to be directed. LED sources or new metal halide lamps have the enormous advantage of being point sources, which means that their optics can be highly tuned. Light goes exactly where it is needed, the ultimate definition of efficiency. There is nothing "muddled" about that.
This is why cities such as San Diego and San Jose, which have suffered for decades under the privations of codes that were leveraged by the astronomers at the Palomar and Lick Observatories, are investigating solid-state lighting, induction, and new metal halide lamp/ballast technology. With newer, cool light technologies, savings in energy and money can be astronomical, with the benefit that we might actually see better at night.
The Dark-Sky lobby, however, doesn't think this is such a good idea. They have produced studies of short wavelength (blue) light and how it can disrupt circadian rhythms at night, how it can actually increase "sky glow" by traveling farther through the atmosphere, and possibly even cause retinal degradation when viewed directly. These studies are solidly researched and should not be disregarded, but the whole point is that there would be so much less light needed in the first place if something other than LPS was used. Carbon footprints would be reduced, greenhouse gasses would be curtailed, maintenance budgets slashed. That is, if the IES would only allow for how our eyes perceive different color temperatures and CRI in their recommended illuminance values. They don't. At least not yet. As stated in their Position Statement PS-02-10, dated August 21, 2010, the "use of "scotopic lumens, scotopic footcandles or other similar scotopic metrics are not valid metrics to be compared to any IES published recommendation." This is highly problematic since most city officials and legislators rely on the IES recommendations to build their codes and ordinances, as does an impending new ordinance: the Model Lighting Ordinance (MLO).
The MLO, which is the flagship of the IDA's attempt to mold a darker world, with the oddly dysfunctional involvement of the IES, stumbles over this issue. It also stumbles over the issue of lumen output, which, as we've seen above, is practically meaningless. In explaining the Prescriptive Method of assessing the light for a site in their User's Guide to the Second Public Review of the MLO, the authors point out that "the values are for initial lamp lumens, not footcandles on the target ... Variables such as the efficiency of the luminaire, dispersion, and lamp wear can affect the actual amount of light so the lumens per square foot allowance is not equal to footcandles on the site. By specifying initial lumen values, it is easier for officials to verify that the requirement is being met." Making things easier for officials to verify doesn't necessarily make for good lighting design.
This is one of many flaws in the MLO. The real issue is directed lumens, or candlepower, which has to take the construction of the specific light fixture into account, not just the lamp or its lumen package or its wattage. For example, I recently lit some palm trees at a mall undergoing "re-imaging" in San Diego with uplights. The uplights complied completely with the San Diego/Palomar code in regard to lumen package of the lamp. A 22W BT5 metal halide lamp was used. Its lumen output falls well below the maximum of 4,050 lumens per lamp stipulated by the San Diego code, but because of its tiny filament, the lamp can be optically optimized within the reflector to provide a 6-degree beam angle, with a candlepower of 46,999. Talk about efficient. A 42W compact fluorescent lamp with a lumen package of 3,200 only puts out 783 maximum candlepower in a similar uplight. The fixture is more efficient because the light is being applied specifically to the targeted object 40 feet up in the air with little spill. The palm trees look great, and provide a monumental, and dare I say, uplifting, experience into the mall. But if the MLO were in place, none of that "uplifting" light would happen.
The MLO is not only built around an obsolete lumen model, it is also built around IES recommendations for light levels that are outmoded, based on the research previously outlined. How the IDA and IES get along is a wonder to me, since the IES is, in effect, saying that it doesn't matter what the color temperature of the source is, just that a certain minimum footcandle requirement is met. This is a disaster for the astronomers in the face of new technology. One footcandle of 4000K LED lighting appears significantly brighter to the human eye than one footcandle of LPS and travels much farther through the atmosphere. We could use much less light, instead, we're pumping needless amounts of short wavelength blue light into the atmosphere to meet what is, in essence, an arbitrary criteria.
Now imagine the "Safest City in America," as recognized by the FBI for five years running, the City of Irvine, Calif. Irvine stipulates a minimum of 1 footcandle on all pedestrian hardscape surfaces. Other cities hoping to emulate Irvine's success in safety are looking to their code. They're also looking to the MLO as a guideline, and they're trying to save energy and money. Only two out of three are possible.
Other than limitations on lumens per square foot, the salient points of the MLO are these: Uplight is bad. Backlight is bad. Glare is bad. There is little nuance to this proposed ordinance. The tables and calculations within the MLO for the more sophisticated, and the slightly more design-friendly Performance Method of determining the amount of light a site may sustain are unwieldy and most likely beyond the ken of any already overworked and understaffed plan-checking department. So is the BUG rating (for Backlight, Uplight, and Glare) for luminaires, which is a system, developed by the IDA and the IES to determine if a luminaire is compliant with Dark-Sky requirements.
What is truly problematic is that the proposed ordinance relies on this rating, but the majority of lighting fixtures are not BUG rated, nor are they likely to be so in the near future due to the inability to be intuitively grasped. What is most likely to happen is that municipalities making the mistake of adopting the MLO in its current form will insist on the simpler Prescriptive Method, which will make it "easier for officials to verify that the requirement is being met," but which shuts down any likelihood of inspiring light, providing only downward tasklighting.
In the world of design, nuance is everything. Uplight can be good; it mimics the light we have seen since man first lit a fire. Backlight can be another person's frontlight and can be used in certain applications to save energy by illuminating more area per watt than fully shielded luminaires, and can provide a transition zone between what is lit and what isn't. One person's glare might be another person's sparkle, a visual element that is exciting because of the ratio between what is lit and what isn't. Judicious use of all of these elements creates design, and perhaps even art.
As another example, part of my duties is to serve as a lighting consultant to one of the largest real estate developers in America. On a weekly basis I am asked to review existing retail, residential, and corporate developments throughout Southern California, many of which have been deemed to be in desperate need of lighting enhancement, very much due to the misapplication of Dark-Sky principles on a collision course with safety codes. Recently I was asked to look at a neighborhood center that was lit to the City of Irvine standard of 1 footcandle minimum. It has one of the brightest parking lots I know. Yet all light was "properly" directed downward, even the pedestrian poles adjacent to the buildings, causing a tremendous disparity between the lit ground and the building façades. There is no light above the walkway. The buildings loom darkly over the patrons. The developer found that his center was not the inviting and thriving establishment he had envisioned, and sales were suffering. After hundreds of thousands of dollars in additional lighting enhancements and hundreds of LED linear wall grazers and spotlights (this is a big center), the architecture finally has a chance to be seen against the night sky. Wayfinding is improved, the center has a new energy, and the owner is content. Yet all of this could have been avoided if the simple initial expedient of using a non-cutoff pedestrian pole had been put in place, as politically incorrect as that sounds, allowing for greater ambient light upwards, and if the City of Irvine hadn't insisted on such a tremendous amount of light on the ground.
I would never argue that there aren't real issues with the electrically illuminated world when there is too much light poorly designed: migratory patterns of birds and sea turtles are disrupted, the balance of ecosystems are shifted, circadian rhythms of human beings are disturbed with certain potential health risks associated. But it was only recently in our evolution that we radically shifted what was possible in the lit environment. There is no way that there wouldn't be some stress on us after hundreds of thousands of years of a different paradigm. As Jane Brox points out, in her book Brilliant: The Evolution of Artificial Light, even a single light in an otherwise lightless environment can shatter existing ecosystems. The choice to use any light has to be carefully weighed, but once it's made, it almost doesn't matter what kind of light it is.
The IDA's notion that there are areas that are currently dark and should remain so is a sound one. Their proposal to establish International Dark Sky Places is very much like the establishment of the National Parks. Perhaps this is where our observatories need to be moved to, as expensive a proposition as that might be. Like the National Parks, if one now wants to experience nature, one might have to leave the urban and even suburban environment. But to insist, in metropolises like San Diego and San Jose, with tens of millions of people affected, that one should limit the quality of the lit environment, especially in a world that now demands that our goods and services travel at all hours of the day or night, is like trying to put the genie back into the lamp.
If the basic tools of lighting design are to be evaluated, it seems to me only fair to question the continued viability of astronomical research from Earth-based telescopes. According to The New York Times on Feb 2, the orbiting Kepler Space Telescope has managed in the two years since it was commissioned to detect more than twice the number of extra-solar planets than Earth-based telescopes did during the previous 15 years. I am not opposed to the spirit of the Dark-Sky movement, which prompts us to live lightly on our planet, nor am I unaware of the risks of over lighting our environment. But I am asking the lighting design community to question and challenge ordinances, codes, and regulations that are poorly written, based on old science and metrics, leave little to no room for artistic expression, and invert a way of experiencing light that goes deep to our human experience. The lighting and design community must be smart enough to take the good part of the IDA's intent and learn from it. But we must also be smart enough to understand that we need more than just stars at night to feel like human beings. We need to celebrate our work, our architecture, our artifacts and our art with light, and that is no less important. •
Peter Maradudin has been working with light for more than 30 years. He has designed over 300 theatrical productions across the country and over 100 architectural projects. He is the Studio Director of StudioK1, the lighting division within the Santa Ana, Calif.-based electrical engineering firm, Konsortum1.