Hit the lights!
New “cut-off” systems provide an all-around solution to tennis court lighting.
Tennis court lighting is an essential part of any good outdoor tennis facility design. Yet what many people fail to appreciate is that good lighting has to be planned for carefully.
Years ago, outdoor tennis lighting usually consisted of high-wattage fixtures located atop tall utility poles. The result was a sea of blinding light that washed over the tennis court surface and the better part of the surrounding neighborhood. While these “high-mast” lighting systems were (and still are) very effective at lighting a tennis game, they tend to degrade the nighttime environment. Moreover, they are often inefficient from the standpoint of energy consumption in that they provide far more light over a far greater surface area than is needed.
To counter this rather crude approach to lighting tennis courts, increasing numbers of municipalities across the country are developing stringent laws governing the control of outdoor lighting in general. The intent with these new laws is to reduce energy consumption and to protect adjacent property owners from excessive light trespass. What’s the alternative? The solution is the cut-off — or shoebox — light.
Developed more than 30 years ago, for use in a variety of situations from parking lots to sports facilities, cut-off tennis lights have a rectangular appearance, like a shoebox. Generally speaking, cut-off lights are mounted on poles between 20 and 25 feet high along the sides of a tennis court. The lights can be mounted individually, in pairs, or by fours on poles, depending upon the court configuration.
The key benefits of a cut-off-type fixture are that the light source is concealed within the box, thereby reducing glare and over-spill, while delivering light in a very concentrated but tightly confined distribution pattern. When seen from a distance, cut-off lighting does not have the upward-directed glow and garish lamp glare associated with a high-mast system.
A properly designed fixture can ensure that there is no more than 1 footcandle of light within 6 to 10 feet of the court’s edge. (One footcandle of light is approximately equivalent to the level of light visible during a full moon on a clear night.) For lighting in municipalities with particularly strict codes, manufacturers can provide glare shields that fasten to the light fixtures to provide additional screening of the light source from outside the court area.
The use of cut-off lighting systems for tennis today is commonplace. There are a number of very reputable manufacturers who sell competitively priced, pre-designed systems specifically for tennis-court applications. Recently, manufacturers have begun producing more streamlined fixtures with thinner profiles and sloping or curved edges that minimize the boxy quality of the early cut-off lighting systems.
In order to ensure that your lighting system will be adequate, here’s some simple advice on what to look for when selecting a cut-off system.
Quantity of Light
Tennis requires surprisingly high levels of light. Inexperienced engineers and lighting designers simply turn to the Illuminating Engineering Society (IES) recommendations to check their standards for sports lighting. Unfortunately, these recommendations are surprisingly low and will produce a rather unsatisfactory result for even the most casual tennis player.
It is strongly recommended that the American Sports Builders Association (ASBA — formerly known as the U.S. Tennis Court and Track Builders Association) standards be used to evaluate your proposed lighting system. Fifty footcandles of light is generally considered a minimum light level for serious recreational players, with 75 to 80 footcandles as a more appropriate level. Footcandles in the range of 85 to 100 are recommended for competitive tennis play.
The quantity of light is especially critical for older players. A 50-year-old player needs six times and a 60-year-old player needs 15 times the light needed by a 20-year-old player. Underestimating light quantity for tennis is perhaps the most common mistake made in lighting design.
Light fixtures tend to age quite dramatically when first put into use. This is often referred to as the initial “burn-in.” Most manufacturers assume at least a 20 percent to 30 percent drop in light levels within the first few months of use. In order to ensure the light level you want over the long term, it is important to specify what is called the “maintained illumination level,” which automatically takes into account the anticipated drop in initial lamp output.
Quality of Light
When considering a lighting system, it is equally important to consider the quality of the light. More light is not necessarily better if the light is not appropriate to the sport. Some key concerns about quality include: uniformity, distribution, and color rendition.
A good lighting system minimizes the differences between hot spots, areas of the most intense light, and darker areas. The less the difference, the more uniform the light is. A tennis ball traveling in and out of light and dark areas is extremely difficult to track visually.
The best way to ensure a uniform lighting system is to specify what is known as the “uniformity ratio” of the system. This is the ratio of the measurement of the darkest areas of the court to the measurement of the lightest areas of the court. A good lighting system will provide a uniformity ratio between 1.5 and 2.0, with 1.5 being at the better end of the scale.
How the light is delivered along the sides of the court can make a big difference to the visibility of the ball. Even with good uniformity of light across the court, if the light fixtures are located in front of the baseline, the ball will have a shadow on the player’s side as it bounces past the fixture toward the backcourt. Excessive shadowing on the ball can be fatiguing for players. This is why a pole layout that provides at least four fixtures per side (with the two outside poles being behind the baseline) generally provides the best distribution of light. The use of fewer poles but more fixtures on top to improve overall quantity of light will save money, but it will compromise the quality of ball visibility in the end.
The color of the light coming from a fixture will depend upon the type of lamp (commonly referred to as the bulb). There are three basic types of lamps used in cut-off-type fixtures: mercury vapor, high-pressure sodium and metal halide.
The most appropriate lamp type for tennis is metal halide, since it provides the clearest, or whitest, light. Mercury vapor produces a very bluish glow, while high-pressure sodium produces a sickly orange glow. While mercury vapor and high-pressure sodium lamps often have a longer lamp life than metal halide, their color rendition make them inappropriate to a quality tennis facility where the court surface color and ball color is important. Again, the use of a particular lamp type to save money on frequency of lamp changing can lead to a compromised quality of light.
Remember, it is well worth your while to play for an extended period of time on a court lit with a cut-off system similar to the one you are considering purchasing to see if it is right for your needs. It is also a good idea to stick with systems that are made for tennis facilities. Cut-off systems for applications other than tennis are deceivingly similar in appearance, but are vastly different when judged on criteria specific for a quality tennis-playing environment.
See all articles by Andrew R. Lavallee
About the Author
Andrew R. Lavallee , ASLA, is a Senior Associate at Mathews Nielsen Landscape Architects, PC located in New York City.