Dark sky regulations have been created throughout the nation to improve the overall quality of lighting while at the same time controlling its quantity. Dark sky laws are intended to minimize glare and obtrusive natural light that often finds its way into homes and neighboring businesses. This type of light pollution is common with fixtures that offer little or no directional control of the light and diffuse too much bright light into all directions in an inefficient attempt to eliminate all shadows. This only results in too much light shining vertically up into the atmosphere, posing a threat to many species of nocturnal animals and blotting out the view of the nighttime sky.



Dark Sky regulations are the result of worldwide efforts on the part of the dark-sky movement. This grass-roots movement began when astronomers became extremely concerned that artificial light from cities was obscuring the view of the stars. A number of associations now operate both nationally and globally to educate the public in the many hazards of uncontrolled artificial light and to help communities adopt dark sky regulations that call for energy efficient, full cutoff lighting fixtures in outdoor environments. These fixtures cast light downward and are ideal for controlling lighting levels in public areas.

The full cutoff fixtures required by dark sky regulations provide businesses and institutions with an alternative to the “blanket” approach to outdoor lighting that previous generations took. Rather than trying to brightly illuminate every corner of a building or commercial property, full cutoff fixtures illuminated only an intended portion from a specific angle of incidence. The purpose of illumination is not to flood the area with light, but rather to shine enough light onto an object or area with enough light to render color and contrast necessary for accurate depth perception and safe mobility.

By calling for a more precise approach to lighting in general, dark sky regulations require contractors to install equipment that benefits both the environment and the city's budget. One of the biggest myths in our industry is the assumption that a large amount of bright light is the key to safety. Studies have proven otherwise. Humans only need just enough light to see contrasts between light and shadows and basic colors. This new data has allowed manufacturers to design fixtures with better, more efficient optics. These newer types of fixtures use reflectors to both aim and control the level of light. Because they rely upon precision rather than sheer power, full cutoff luminaires can do more work with fewer watts. This is why dark sky regulations now limit HID lighting fixtures to a 250 watts maximum and compact fluorescent lights to 25 watts maximum. These changes, although momentarily inconvenient to those who have to replace equipment to comply with dark sky regulations, will pay off in the long run with lower energy costs, improved general safety thanks to the reduction in glare, and a better overall aesthetic.

Dark sky regulations often mandate lighting curfews that require lights in certain areas to be turned off after businesses are closed and traffic is minimal. Contractors who outdoor lighting systems in an area such as this should use motion controlled sensors as much as possible. This will allow the lights to come back on if a person or vehicle approaches the areas. Other steps should be taken by the contractor to minimize the possibility of light trespass into adjoining properties and streets. Signs should be fully shielded, and landscape lighting should operate without glare. Luminaires such as sign lights, building lights, and step lights that are not specifically regulated by dark sky laws nevertheless have similar, separate codes that need to be followed. Dark sky regulations are flexible to an extent when it comes to athletic and sports field lighting, provided the local authority has certified them in writing to minimize glare and light trespass and operate within acceptable hours for sporting events.