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OAAA Issue Brief






















Illumination is fundamental to effective outdoor advertising, a
round-the-clock mass communication medium


Limits on lighting hurt the traveling public, advertisers and public
safety


Billboard lighting is a tiny fraction of the overall ambient light level

















OAAA Issue Brief

Outdoor Lighting and Dark Skies
Outdoor Lighting and Dark Skies: An OAAA Issue Brief
Outdoor Lighting and Dark Skies: An OAAA Issue Brief March 2008
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In a mobile society, outdoor lighting is an essential part of commerce and
security. Anti-lighting proponents seek to damage the effectiveness of illuminated
outdoor advertising by placing arbitrary lighting limits. Restrictions on lighting
undermine the business of outdoor advertising by requiring costly retro-fitting of
sign structures or elimination of lighting fixtures.

Based on a March, 2008 report by Lighting Sciences, Inc, Phoenix, AZ, the
OAAA has recommended brightness criteria for digital billboards - suggesting
that light produced by digital billboard structures should not exceed 0.3
Footcandles over ambient light levels. A summary of this report follows as a
reference.

Lighting on outdoor advertising structures is a tiny fraction of the overall ambient
light level. A previous report by Lighting Sciences, Inc. concludes that most sky
glow some 96 percent is produced by sources other than billboards. A
summary of this report is enclosed as a reference.

Plus, a new generation of halogen lights is more efficient, requiring only two
fixtures to illuminate a standard bulletin rather than three or four fixtures. These
new fixtures also direct the light source more evenly onto the face of the
bulletins, eliminating most of the ambient light spillage around a bulletin edges,
reducing energy consumption.


Light equals security: Illumination enhances public safety and security. Lack
of adequate lighting can compromise safety, promote criminal activity, damage
consumer confidence, and depress nighttime commerce.

State legislatures have rejected lighting restrictions: Numerous law-making
bodies have considered, but rejected prop proposals. In 2007, Montana and
Wyoming defeated proposals to limit lighting.


In 1999, New Mexico enacted the Night Sky Protection Act, which sought to
strike a balance of preserving and enhancing the states dark sky while
promoting safety, security, and conserving energy. The Act exempts outdoor
lighting fixtures on advertisement signs on interstates and federal-aid primary
highways, as well as other lighting such as navigational lighting systems at
airports.



The Griffith Observatory in California uses outdoor advertising
Outdoor Lighting and Dark Skies: An OAAA Issue Brief
Outdoor Lighting and Dark Skies: An OAAA Issue Brief March 2008
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References
OAAA Recommended Brightness Guidelines, based on a report from Dr. Ian
Lewin, Principle, Lighting Sciences Incorporated, Scottsdale, AZ, March, 2008

General Outdoor Advertising Lighting Guidelines, Illuminating Engineering
Society of North America (IESNA), 2003

A Preliminary Estimation of the Impact of Billboard Lighting on Sky Glow,
Executive Summary, Ian Lewin, Ph.D, FIES, L.C., Lighting Sciences Inc.,
Phoenix, AZ

New Mexico Night Sky Protection Act, 1999
































Outdoor Lighting and Dark Skies: An OAAA Issue Brief
Outdoor Lighting and Dark Skies: An OAAA Issue Brief March 2008
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OAAA Recommended Brightness Guidelines

A. OAAA Guidelines: The OAAA recommended brightness criteria for digital
billboards is as follows:
Light produced by a digital billboard should not exceed 0.3 Footcandles over
ambient light levels. Measurement should be taken utilizing a Footcandle meter from the following
distances (perpendicular to the face of the digital billboard):
Posters: 150 feet

10'6x36 Bulletins: 200 feet
14x48 Bulletins: 250 feet
20x60 Bulletins: 350 feet
The measurement distances are based on the average minimum viewing
distances for each type of billboard. Digital billboards must have automatic dimming capability.

B. Basis for the Guidelines. These guidelines are based on recommendations
by Dr. Ian Lewin of Lighting Sciences Inc. (Scottsdale, AZ) in a March, 2008
report to the OAAA. Dr. Lewin developed brightness criteria to meet the following
general guidelines:
Appropriately
Legible
Copy. Digital advertising copy is appropriately legible
and not overly bright. Simplicity. Provide a guideline that can be easily implemented and enforced.
Measurement of the ambient light level of the sign on and off is conducted by
a footcandle meter. If the difference in measurements is less than 0.3
footcandles, the digital billboard is in compliance. Established
Guidelines. The criteria is based on established scientific
methodology and established industry standards from the Illuminating
Engineering Society of North America (IESNA) publication TM-11-00 light
trespass theory which is an accepted standard in the lighting industry. Flexibility. Ensure proper brightness levels in a variety of lighting
environments.

C. Additional Issues/Clarification
Automatic Dimming Capability. A digital billboard must be able to
automatically adjust as ambient light levels change. An automatic light
sensing device (such as photocell or similar technology) should be utilized for
adjusting the digital billboards brightness. Sunset-sunrise tables and manual
methods of controlling brightness are not acceptable as a primary means of
controlling brightness. Brightness Measurement Methodology. The brightness standard requires
the use of a Footcandle meter (also known as a Lux meter; ~$100-1000). A
Footcandle meter measures the amount of light arriving at the meter
(illuminance), as opposed to an absolute measurement of the amount of light
emanating from a light source or light sources (luminance). A Footcandle is a Outdoor Lighting and Dark Skies: An OAAA Issue Brief
Outdoor Lighting and Dark Skies: An OAAA Issue Brief March 2008
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measure of lumens (light rays) that fall on one square foot area; Lux is the
metric equivalent of a Footcandle.

In contrast, a Candela Meter / NIT Gun (~$3,000) measures the amount of light
emanating from a specific light source (luminance). A NIT gun measures
candelas (a measure of luminance or brightness) per meter squared (also known
as NITS), which is a measure of the brightness emanating from a specific light
source. It excludes ambient light (which may include light from many sources)
from the measurement. Standard NIT levels and/or utilization of a NIT gun are
not a part of the OAAA recommended brightness guideline.


General Outdoor Advertising Lighting Guidelines referenced by the
Illuminating Engineering Society of North America (IESNA)



A billboard can be illuminated either by fixtures located in front of the sign (front
lit), from behind the sign (back lit) or from fixtures mounted away from the sign
(remote). Each mounting location will present different issues:

Front lit / Top Mount May increase installation cost due to need
for additional structure elements. Orientation of the fixture may create veiling
glare and direct glare to the viewer. May possibly reduce the sky glow. Increased maintenance cost. Location interferes with changing of the
sign message. Interferes
with
use
of embellishments or
cutouts. Daytime shadowing will detract from the
readability of the sign.

Front lit / Bottom Mount Ability to mount fixtures to catwalks eases
maintenance. Properly designed optical system will
minimize sky glow. Does not interfere with changing of the sign
message. Does not interfere with the use of
embellishments. No daytime shadowing. Light source less likely to create veiling
glare.
Outdoor Lighting and Dark Skies: An OAAA Issue Brief
Outdoor Lighting and Dark Skies: An OAAA Issue Brief March 2008
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Remote Light source able to cover larger sign
surface. Maintenance may be easier when mounted
on the ground. May require additional wiring and
installation cost. May contribute to sky glow.

Back lit Requires significantly more luminaires to
illuminate the sign. Depends on the transmittance
characteristics of the vinyl. Increase maintenance and installation cost. Cost to produce the translucent vinyl media
for backlight signs may be more expensive
than traditional methods. Lamp sources used are typically less
efficient and consume more energy.

Sign face brightness depends on the







transmittance characteristics of the vinyl
or other face ma