Lighting the "Great Out-of-Doors" for Functionality and Effect
Lighting in the great out-of-doors can be as diverse as the outdoor setting itself. Whatever the application—whether a park, commercial building, city scape or college campus—appearance is only one factor. In many instances, lighting the area for functionality may be an even higher priority.
When designing the illumination for an outdoor application, the first inclination may be to light for drama and effect, to emphasize architectural detail, spotlight foliage, or display the intricacies of a work of art, such as a statue or monument. While drama in an outdoor setting is enticing from a distance, in most instances, the space will be more comfortable and inviting if it is illuminated for the people who utilize it. When the lighting fails to make the space usable after dark, the lighting system may be considered unsuccessful.
Defining Lighting Objectives
No matter what the application, the first step in designing the lighting system should be to determine the goals of the application. Is the objective drama, functionality—or a combination? Is this a “people space” where security is an issue? Is it important to highlight the surroundings, such as the trees in a park or the overhead foliage in a ravine?
At the College of William and Mary in historic Williamsburg, Virginia, student safety was the primary objective when the existing lighting system was retrofit. Administrators wanted fixtures that would project the illumination farther down the walkways—as opposed to directly around the poles. Mushroom-shaped fixtures with white plastic reflectors and 250-watt mercury vapor lamps, which had been installed 35 years earlier, tended to shine straight down. The result was dark spots that led to frequent student requests for additional fixtures that could be mounted between the existing poles.
In Toledo, Ohio, the Toledo Museum of Art—a Frank Gehry building—is a distinct landmark in the Old West End Historic District. When lighting was installed to illuminate the 95-year-old structure’s marble and sandstone facade and 30 Ionic columns, the objectives were to enhance the building’s appearance at night and to heighten the experience for every patron who walked through the Museum’s front doors. Other goals were to create a greater sense of security and encourage families to visit the museum at night.
In San Diego, city fathers wanted to install a lighting system in the Center City district, an area where crime had become such a problem that people feared for their safety after dark. The goal was to begin to position San Diego as a 24-hour city and to draw people downtown at night—with the hope that this warehouse district would evolve into a more residential area with a mix of businesses.
Creating a Visual Environment
In each of the applications described above, the goals could be met by creating an open visual environment that would allow the inhabitants within the spaces to discern detail. Perhaps silhouette lighting would be sufficient to illuminate the Ionic columns at The Toledo Museum of Art or vehicles driving along the streets of downtown San Diego. But this type of lighting would not allow space occupants to determine details and specific characteristics.
Silhouette lighting is often used for roadways and parking lots where the primary objective is to avoid collision with objects and other vehicles. In these types of applications, illumination that outlines objects enough so that their presence is noted will likely suffice. Silhouette lighting will not, however, provide the illumination needed to determine details such as whether a person entering the space is a man or a woman, how the person is dressed or his or her facial expression, or whether the person is holding anything in his or her hand. Often, the occupant will not be able to discern whether the newcomer is approaching or walking away.
To provide safety from attack in a park or on a city street, it is important not only to see that an object (in this case, a person) is approaching, but to recognize facial features and other characteristics that might suggest whether the person poses a threat. Unless the passer-by has some well-known peculiarity of figure or gait, he or she will not be identifiable when silhouette lighting is the only source of illumination.
In most outdoor applications, the overall objective is to create an environment that looks nearly the same at night as it does during the day. The space should be bright and inviting, and free of shadows. This can best be accomplished with a direct source of illumination that will facilitate the recognition of details.
The Toledo Museum of Art is illuminated with floodlights mounted at ground level on 18-inch bases. The fixtures have a fluted reflector that maximizes the lighting uniformity and emphasizes the building’s many shapes and angles. To illuminate the Museum’s entrances, cutoff fixtures with 100-watt deluxe metal halide lamps are installed beneath the Museum’s portico at the top of the columns. The latter units are used to brighten the area immediately behind the columns and to emphasize the entrances.
“The effect is quite dramatic,” said Paul Bernard, manager, physical plant/physical facilities team leader, The Toledo Museum of Art. “We have received many positive comments on the lighting from visitors, residents and city officials.”
Creating illumination on both the vertical and horizontal planes will help emphasize details within the space and will minimize shadows since the light reaches objects from more than one source. Vertical illumination with a high angle intensity will effectively light a building facade—both above and below the luminaire—so the landscape looks almost the same at night as it does during daylight. Adding a degree of controlled uplight will illuminate shrubs and overhanging branches to eliminate the “tunnel effect,” which can result when a lighted area is dark overhead.
On the courthouse Square in Newark, Ohio, fixtures that provide vertical illumination and controlled uplight have created an environment that is “light enough at night that someone could play tennis on the lawn,” according to Newark Parks and Recreation superintendent, Terry Frame.
“We wanted people to feel safe and to bring their families downtown at night. With the new lighting system, we have promoted a sense of security,” Frame said.
In applications where sky glow and light trespass are an issue, the designer must decide whether uplight is desirable. San Diego, for example, has a perceived light pollution problem. With two observatories located within 50 miles of the city, astronomers often complain about the brightness of the city at night.
When the city launched the lighting project in its Center City area, an extensive research and field testing project was implemented to determine what type of fixtures and light distribution patterns would be the most effective. The fixtures had to direct the light downward onto the street and sidewalk, instead of upward. The solution was a double globe fixture with an optical system that would shine the light where it was needed.
Lighting for Dramatic Effect
Lighting for functionality does not mean the designer must sacrifice drama. Drama can be achieved with contrast and shadows provided by floods and spotlights. Providing light from an overhead source—as though the fixtures were floating in a hot air balloon—will also promote drama, although this type of lighting will be the least informative.
Floodlighting and spotlighting in a landscape will provide high enough levels of illumination so that security personnel will be able to determine whether someone has entered the space and whether the area is threatened. These sources of illumination will also emphasize architectural detail and will showcase foliage. However, floodlights and spotlights that provide illumination levels upwards of 50 footcandles will not be comfortable for pedestrians.
In many instances, creating an open visual environment with vertical illumination and controlled uplight will fulfill the designer’s lighting objectives. A good design will make it possible to highlight a building, a pathway or a sculpture while still promoting functionality.