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Where the Light Meets the Dark

by Stephen Kelly, managing editor

The Long Island Power Authority Bridgehampton yard with 1,000 watt floodlights, and after, with 400-watt full cutoff Mongoose luminaires.

Photometry is the science of design of optical systems, the measurement of their efficiency, and the control of light, including light pollution and light trespass. Light can be directed through the use of various optical systems to produce different degrees of efficiency. Selecting the correct optical system necessitates considering luminaire style, environmental concerns, energy efficiency and the required lighting performance.

Fly into any major urban area and the issue of light pollution is driven home. Looking down on the city from a few thousand feet is quite appealing. The lighting looks decorative, in the same way a Christmas tree is pleasing to the eye. But as you get closer to the ground, there's a point where the glare comes up to meet and envelope you.

A U.S. night, cloud-free composite image taken by the DMSP (Defense Meteorological Satellite) from Oct. 1, 1994, to March 31, 1995. NOAA (the National Oceanic and Atmospheric Administration) processed the data from the National Environmental Satellite, Data, Information Service satellite.

LASN is published out of Southern California. We don't get to see much in the way of stars here, unless we head up into the local mountains or go to a dark stretch of beach. I used to walk with some of my co-workers years ago down a little road at night on the island of Kauai near Hanalei Bay, Hawaii, to the house of our boss. He liked to entertain and would lay out a big spread to feed and "water" all. That road was so dark you literally could not see your hand in front of you. We'd end up bumping into one another and laughing, and gazing all the while up at a sky so full of stars that it was surreal.

You'll see by the satellite night photo of the U.S. that there's still plenty of space in this country to see the stars as our forefathers did, but alas, most of us live and work in the urban environment.

The night sky on the Eastern seaboard August 13, 2003, the night before the blackout.

There's a worthwhile organization that works to help us urbanites see a little more of what's up there--the International Dark-Sky Association (IDA). The IDA, incorporated in 1988 as a nonprofit organization, seeks to "preserve and protect the nighttime environment and our heritage of dark skies." The IDA builds awareness and finds solutions to the adverse environmental impact of light pollution on our night skies. The solution, generally speaking, can be found in this seven-word mantra: fully shielded lights at low illumination levels.

Each March, the IDA holds its annual conference and presents awards in a number of categories to those who have "demonstrated a commitment to the IDA and its philosophies." The first place winner last year (the 2004 contest results won't be in before this goes to press) went to the lighting for Ironwood Ridge High School in the Amphitheater School District of Tucson, Arizona. The award was presented to Chris Monrad, president of Monrad Engineering, Inc.

The August 14, 2003 blackout.

The first runner-up was the Gentilini Ford Dealership in Woodbine, New Jersey, exterior lighting installation designed by Stanker and Galletto Company in Vineland, NJ. The judges commented: "This installation shows responsible lighting in an otherwise 'light competitive' environment. The controls and design were excellent, and the installation sets an example for car dealerships in the entire region."

Among the other awards, was an international lighting award to Calgary, Alberta, Canada for the city's energy conservation of converted 40,000 streetlights to fully-shielded fixtures. The city is reducing the wattages from 200 to 100, estimated to save $2 million in energy costs per year.

The Hungarian National Railways was also awarded for its initiative to begin replacing 16,000 lights with fully-shielded fixtures and cutting the wattage in half.

Mr. Tamas Deri in Budapest was the project manager.

Lighting ATMs to meet IDA standards and state law is a difficult proposition, but the Charter One Bank in Albany, New York, was recognized for doing just that. Naomi Miller Lighting Design in Troy, New York, was able to adequately light ATMs while controlling glare and "light trespass" to create a pleasant ambience. The judges deemed the lighting an "example for how to design exterior lighting all banks in the state."

IDA Gets Results

On October 21, 2003, Richard Kessel, chairman of the Long Island Power Authority (LIPA), announced the first installation of dark sky lighting at its Bridgehampton, Long Island, New York yard, a dramatic difference lauded by the IDA. Gary Citro, Gail Clyma and Susan Harder of the Dark Sky Society of Long Island were on hand for the announcement, as was New York State Assemblyman Fred Thiele Jr.

King Luminaire

VL1 The Louvered Reflector provides cutoff and semi-cutoff performance. The spun aluminum specular louver system reflects and redirects the light, enabling acorn and globe luminaires to meet most luminance requirements, and providing excellent efficiency with low glare.

VL2 The Segmented Reflector is a sophisticated segmented aluminum reflector specifically designed to minimize glare and uplight in post top and pendant luminaires, providing cutoff characteristics.

VL3 The Hydroformed Reflector directly addresses the issues of glare, light pollution and light trespass without significant loss of efficiency. This optical system is capable of producing cutoff and full cutoff light classification, utilizing a horizontal lamp.

The facility's bright and glaring nighttime lighting had long been the source of many complaints. Mr. Kessel said the new lighting meets the dusk-to-dawn lighting needs of the facility, while respecting "one of Long Island's most precious natural resources, the dark night sky." The new fixtures, 400 watt full cutoff Mongoose luminaires from Holophane, are shielded, illuminating directly downward and eliminating up and side glare. Further, as each of the 16,000 1,000 watt floodlights of LIPA customers burns out, or when the business leasing them changes hands, the offending lights will be replaced by the 400 watt cutoff luminaires.

In another nod to the dark-skies effort, LIPA will also be adding educational material regarding sensible outdoor lighting practices to its website. Robert Kessel admitted the utility company previously viewed nighttime lighting basically in terms of revenue, but he now sees steps to reduce sky glow as an investment in the community.

SELENE, the IDA's New York State affiliate, saluted LIPA management for responding to public concerns and recognizing the need to reduce light pollution.

Post-Top Period Lighting

Post-top period lighting is attractive and fun. The Henry Ford Greenfield Village featured in our March issue, for instance, used different period post tops throughout the park, depending on the historical venue.

Period post tops, however, are controversial in the dark sky community. The IDA states: "If IDA recommended lighting fixtures, we would not recommend these for anything except for historical areas, and then only when there are strong reasons for the choice."

The IDA's 2003 first place Dark Sky winner: Left The entry to Ironwood Ridge High School, Tucson, Arizona.

The school's west parking lot. Project electrical engineer/lighting designer: Monrad Engineering, Inc., Consulting Electrical Engineers, Tucson, AZ. Project architects: EMC2 Group, Mesa AZ.

The problem comes, the IDA explains, with trying to use historical lighting tops for lighting and decoration, two separate, distinct functions. The needs are different and should be met by different schemes. The IDA recommends the minimum amount of lumens; after all, glare from too much light obscures those pretty period tops. There are lamps and fixtures that address glare, light trespass, uplight, light pollution, energy waste and still provide historic appearance.

The Parklane 2700 from the Pennsylvania Globe and Gaslight Co., for instance, has a full cutoff and is considered "dark sky friendly" by the IDA. Other companies, like King Luminaire, make historic post tops with cutoff luminaires with less than 2.5% up light.

What often happens in historical areas or older parts of cities and towns, according to the IDA, is that old fixtures are retrofitted with higher output lamps, basically with no consideration for the optical effect or the area's nighttime ambiance. The IDA believes these fixtures should be confined to high ambient lit urban areas.

The decorative garden series (DGS) low-level lighting from LSI Greenlee.

While IDA does not recommend or endorse luminaires fixtures, it does list as of Oct. 10, 2003, 150 different ones from over 80 manufacturers that meet "good lighting." The IDA notes that "a manufacturers must have one or more fully-shielded fixture to be listed." The IDA further list the fixtures in 24 lighting areas.

And Dark Skies Said, "Let There Be a Lighting Code"

The IDA Outdoor Lighting Code Handbook and USA Pattern Lighting (the handbook), is described by the IDA as a comprehensive guide for any community of any size to control obtrusive outdoor lighting and the regulatory approaches to succeed. Outdoor lighting codes, often part of the zoning or land-use code for a locality, establish and define permitted and prohibited lighting practices, with an emphasis on limiting intrusive lighting. Lighting codes are enacted at various levels, from developments and neighborhoods to city, county and state codes. State-level codes tend to address general aspects of lighting built with state funding, however, state lighting codes facilitate the adoption of more comprehensive, rigorous local lighting codes.

Like any codes, lighting codes must not only be well written and defined, but implemented and enforced. When they are, the IDA terms the improvements achieved as "nothing short of phenomenal." The basic intent of a lighting code is eliminating glare, whether gratuitous uplighting or just subpar lighting.

The Accent Star(TM) from B-K Lighting utilizes a MR16 lamp (to 50 watts) recessed into a housing, which lights indirectly into the etched Pyrex glass lens and reflector, giving the fixture a low-brightness appearance.

The shielding standards recommended in the handbook, according the IDA, virtually eliminate glare and reduce light escaping into the sky by 50 percent or more compared to typical unregulated lighting practices.

The adoption of a lighting usually begins, as with most initiatives, with a motivate person or group especially tuned into the many values of quality lighting. The IDA handbook emphasizes "practicality of application and enforcement." Definitions must be technically correct yet clear and understandable to lighting users, designers and planners.

Complicating the mix is that different areas have disparate development and contrasting natural conditions, thus incongruous levels of appropriate lighting. The handbook takes this into account by designating five lighting zones and lighting standards appropriate to each. The zones are based on the CIE Environmental Zones, ranging from dark landscapes up through the near daylight brightness of urban centers.

Spring City's Franklin Gooseneck horizontal lamp, Type III, cutoff, is 39 1/8 inch tall, made of cast aluminum alloy with a clear polycarbonate panel.

While the IDA judges overlighting increasingly prevalent, its handbook "avoids wherever possible technical lighting specifications." The IDA explains it could use the recommended lighting levels defined by the Illuminating Engineering Society of North America, but believes the control of the "majority of overlighting problems can be addressed effectively by an overall cap on the amount of light permitted, scaled to the area to be developed (lumens per acre caps)." The IDA reasoning is that the amount of light in a design measured in lumens is practical and simple to verify from a simple list of lamps, and requires no special lighting expertise. It leaves the maximum flexibility for the lighting designer, while at the same time keeping a cap on the total amount of light used.

The luminaires are just a small sample of good night lighting on the IDA website. For more information on good night lighting, go to the International Dark-Sky Association website at

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June 18, 2019, 8:40 am PDT

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