Lighting

From Wikipedia, the free encyclopedia

Not to be confused with lightning.

For other uses, see lighting (disambiguation).

Low-intensity lighting and haze in a concert hall allows laser effects to be visible

Daylight used at the train station Gare de l'Est Paris

Lighting or illumination is the deliberate application of light to achieve some aesthetic or practical effect.
Lighting includes use of both artificial light sources such as lamps and natural illumination of interiors
from daylight. Daylighting (through windows, skylights, etc.) is often used as the main source of light during
daytime in buildings given its low cost. Artificial lighting represents a major component of energy consumption,
accounting for a significant part of all energy consumed worldwide. Artificial lighting is most commonly provided
today by electric lights, but gas lighting, candles, or oil lamps were used in the past, and still are used in certain
situations. Proper lighting can enhance task performance or aesthetics, while there can be energy wastage and
adverse health effects of poorly designed lighting. Indoor lighting is a form of fixture or furnishing, and a key
part ofinterior design. Lighting can also be an intrinsic component of landscaping.

Contents
[hide]

• 1 Fixtures

○ 1.1 Types

○ 1.2 Methods

○ 1.3 Forms of Lighting

 1.3.1 Indoor

Lighting

 1.3.2 Outdoor

Lighting

• 2 Vehicle use

• 3 Lamps

• 4 Design and architecture

• 5 Measurement

○ 5.1 Color Properties

○ 5.2 Light Exposure

• 6 Energy consumption

• 7 Health effects

• 8 Environmental issues

• 9 Military use

• 10 Professional organizations

○ 10.1 International

○ 10.2 National

• 11 See also

○ 11.1 Inventors

○ 11.2 Lists
 • 12 Footnotes

• 13 Sources

• 14 External links

[edit]Fixtures

Main article: Light fixture

Lighting fixtures come in a wide variety of styles for various functions. The most important functions are as a
holder for the light source, to provide directed light and to avoid visual glare. Some are very plain and
functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can
tolerate the excess heat and is in keeping with safety codes.

An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of
usable light emanating from the fixture per used energy, usually measured inlumen per watt. A fixture using
replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb"
to the surroundings. The more transparentthe lighting fixture is, the higher efficacy. Shading the light will
normally decrease efficacy but increase the directionality and the visual comfort probability.

[edit]Types

A demonstration of the effects of different kinds of lighting

Lighting is classified by intended use as general, localized, or task lighting, depending largely on the distribution
of the light produced by the fixture.

 Task lighting is mainly functional and is usually the most concentrated, for
purposes such as reading or inspection of materials. For example, reading
poor-quality reproductions may require task lighting levels up to
1500 lux (150 footcandles), and some inspection tasks orsurgical procedures
require even higher levels.
  Accent lighting is mainly decorative, intended to highlight pictures, plants, or
other elements of interior design or landscaping.

 General lighting (sometimes referred to as ambient light[1]) fills in between the

two and is intended for general illumination of an area. Indoors, this would be
a basic lamp on a table or floor, or a fixture on the ceiling. Outdoors, general
lighting for a parking lot may be as low as 10-20 lux (1-2 footcandles)
since pedestrians and motorists already used to the dark will need little light
for crossing the area.
[edit]Methods

 Downlighting is most common, with fixtures on or recessed in the ceiling

casting light downward. This tends to be the most used method, used in both
offices and homes. Although it is easy to design it has dramatic problems with
glare and excess energy consumption due to large number of fittings.

 Uplighting is less common, often used to bounce indirect light off the ceiling
and back down. It is commonly used in lighting applications that require
minimal glare and uniform general illuminance levels. Uplighting (indirect)
uses a diffuse surface to reflect light in a space and can minimize disabling
glare on computer displays and other dark glossy surfaces. It gives a more
uniform presentation of the light output in operation. However indirect lighting
is completely reliant upon the reflectance value of the surface. While indirect
lighting can create a diffused and shadow free light effect it can be regarded
as an uneconomical lighting principle.

 Front lighting is also quite common, but tends to make the subject look flat as
its casts almost no visible shadows. Lighting from the side is the less
common, as it tends to produceglare near eye level. Backlighting either
around or through an object is mainly for accent.
Wall-mounted light with shadows

[edit]Forms of Lighting
[edit]Indoor Lighting

Forms of lighting include alcove lighting, which like most other uplighting is indirect. This is often done
with fluorescent lighting or rope light, or occasionally with neon lighting. It is a form of backlighting.

Soffit or close to wall lighting can be general or a decorative wall-wash, sometimes used to bring out texture
(like stucco or plaster) on a wall, though this may also show its defects as well. The effect depends heavily on
the exact type of lighting source used.

Recessed lighting (often called "pot lights" in Canada, "can lights" or 'high hats" in the U.S.) is popular, with
fixtures mounted into the ceiling structure so as to appear flush with it. These downlights can use narrow beam
spotlights, or wider-angle floodlights, both of which are bulbs having their own reflectors. There are also
downlights with internal reflectors designed to accept common 'A' lamps (light bulbs) which are generally less
costly than reflector lamps. Downlights can be incandescent, fluorescent, HID (high intensity
discharge) or LED.

Track lighting, invented by Lightolier, was popular at one point because it was much easier to install than
recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some
popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not
have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in
themselves. A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of
each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well
as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or
clipped to bare metal cables under tension.

A sconce is a wall-mounted fixture, particularly one that shines up and sometimes down as well. A torchiere is
an uplight intended for ambient lighting. It is typically a floor lamp but may be wall-mounted like a sconce.

The portable or table lamp is probably the most common fixture, found in many homes and offices. The
standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered task
lighting. Magnifier lamps are also task lighting.
Animated fountain in Moscow's Square of Europe, lit at night.

The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. This
uses diffuser panels hung like asuspended ceiling below fluorescent lights, and is considered general lighting.
Other forms include neon, which is not usually intended to illuminate anything else, but to actually be an
artwork in itself. This would probably fall under accent lighting, though in a dark nightclub it could be considered
general lighting.

In a movie theater each step in the aisles is usually marked with a row of small lights, for convenience and
safety when the film has started, hence the other lights are off. Traditionally made up of small low wattage, low
voltage lamps in a track or translucent tube, these are rapidly being replaced with LED based versions.

[edit]Outdoor Lighting

High mast lighting along Highway 401 inOntario, Canada.

Street Lights are used to light roadways and walkways at night. Some manufacturers are designing LED and
photovoltaic luminaires to provide an energy-efficient alternative to traditional street light fixtures[2][3][4].
Floodlights are used to illuminate outdoor playing fields or work zones during nighttime.

Floodlights can be used to illuminate outdoor playing fields or work zones during nighttime hours. The most
common type of floodlights are metal halide and high pressure sodium lights.

Beacon lights are positioned at the intersection of two roads to aid in navigation.

Security lights can be used along roadways in urban areas, or behind homes or commercial facilities. These
are extremely bright lights used to deter crime. Security lights may include floodlights.

Entry lights can be used outside to illuminate and signal the entrance to a property[5]. These lights are installed
for safety, security, and for decoration.

Underwater accent lighting is also used for koi ponds, fountains, swimming pools and the like.

[edit]Vehicle use

Main article: Automotive lighting

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the
front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many
manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps[6]. Tail
and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following
drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the
reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn
signals on the front, side, and rear of the vehicle indicate an intended change of position or direction.

In addition to lighting for useful purposes, manufacturers would sometimes backlight their logos and or other
translucent paneling in the 1970s. In the 1990s, a popular trend was to customize vehicles with neon lighting,
especially underneath the body of a car. In the 2000s, neon lighting is increasingly yielding to digital vehicle
lighting, in which bright LEDs are placed on the car and operated by a computer which can be customized and
programmed to display a range of changing patterns and colors, a technology borrowed from Christmas lights.
[edit]Lamps

Main article: Lamp (electrical component)

Commonly called 'light bulbs', lamps are the removable and replaceable portion of a luminaire which converts
electrical energy to both visible and non-visible electromagnetic energy. Specialists who work with lighting,
carefully avoid energetic units for measuring of the light output of sources of light due to the spectral response
of human visual perception. For example, instead of watt per steradian, the special unit candela is used; 1
candela=(1/683) W/steradian for monochromatic light at 555 nm wavelength. Common characteristics used to
evaluate lamp quality include efficacy measured in lumens per watt, typical lamp life measured in hours,
and Color Rendering Index on a scale of 0 to 100. Cost of replacement lamps is also an important factor in any
design.[7]

[edit]Design and architecture

Main article: Architectural lighting design

Lighting without windows: The Pantheonin the 18th century, painted by Giovanni Paolo Panini.[8]

Lighting design as it applies to the built environment, also known as 'architectural lighting design', is both a
science and an art. Comprehensive lighting design requires consideration of the amount of functional light
provided, the energy consumed, as well as the aesthetic impact supplied by the lighting system. Some
buildings, like surgical centers and sports facilities, are primarily concerned with providing the appropriate
amount of light for the associated task. Some buildings, like warehouses and office buildings, are primarily
concerned with saving money through the energy efficiency of the lighting system. Other buildings, like casinos
and theatres, are primarily concerned with enhancing the appearance and emotional impact of architecture
through lighting systems. Therefore, it is important that the sciences of light production and luminaire
photometrics are balanced with the artistic application of light as a medium in our built environment. These
electrical lighting systems should also consider the impacts of, and ideally be integrated
with, daylighting systems. Factors involved in lighting design are essentially the same as those discussed
above in energy conservation analysis.

For simple installations, hand-calculations based on tabular data can be used to provide an acceptable lighting
design. More critical or optimized designs now routinely use mathematical modeling on a computer.

Based on the positions and mounting heights of the fixtures, and their photometric characteristics, the proposed
lighting layout can be checked for uniformity and quantity of illumination. For larger projects or those with
irregular floor plans, lighting design software can be used. Each fixture has its location entered, and the
reflectance of walls, ceiling, and floors can be entered. The computer program will then produce a set of
contour charts overlaid on the project floor plan, showing the light level to be expected at the working height.
More advanced programs can include the effect of light from windows or skylights, allowing further optimization
of the operating cost of the lighting installation.

The Zonal Cavity Method is used as a basis for both hand, tabulated, and computer calculations. This method
uses the reflectance coefficients of room surfaces to model the contribution to useful illumination at the working
level of the room due to light reflected from the walls and the ceiling. Simplified photometric values are usually
given by fixture manufacturers for use in this method.

Computer modeling of outdoor flood lighting usually proceeds directly from photometric data. The total lighting
power of a lamp is divided into small solid angular regions. Each region is extended to the surface which is to
be lit and the area calculated, giving the light power per unit of area. Where multiple lamps are used to
illuminate the same area, each one's contribution is summed. Again the tabulated light levels (in lux or foot-
candles) can be presented as contour lines of constant lighting value, overlaid on the project plan drawing.
Hand calculations might only be required at a few points, but computer calculations allow a better estimate of
the uniformity and lighting level.

Practical lighting design must take into account the gradual decrease in light levels from each lamp owing to
lamp aging, lamp burnout, and dirt accumulation on fixture and lamp surfaces. Empirically-established
depreciation factors are listed in lighting design handbooks.

[edit]Measurement

Luminance is a photometric measure of the density of luminous intensity in a given direction. It describes the
amount of light that passes through or is emitted from a particular area, and falls within a given solid angle.
The SI unit for luminance is candela per square metre (cd/m2). The CGS unit of luminance is the stilb, which is
equal to one candela per square centimetre or 10 kcd/m2.
[edit]Color Properties
To define light source color properties, the lighting industry predominantly relies on two metrics, correlated
color temperature (CCT), commonly used as an indication of the apparent “warmth” or “coolness” of the light
emitted by a source, and color rendering index (CRI), an indication of the light source’s ability to make objects
appear natural.

However, these two metrics, developed in the last century, are facing increased challenges and criticisms as
new types of light sources, particularly light emitting diodes (LEDs), become more prevalent in the market.

For example, in order to meet the expectations for good color rendering in retail applications,
research[9] suggests using the well-established CRI along with another metric called gamut area index (GAI).
GAI represents the relative separation of object colors illuminated by a light source; the greater the GAI, the
greater the apparent saturation or vividness of the object colors. As a result, light sources which balance both
CRI and GAI are generally preferred over ones that have only high CRI or only high GAI.[10]

[edit]Light Exposure
Typical measurements of light have used a Dosimeter. Dosimeters measure an individual's or an object's
exposure to something in the environment, such as light dosimeters and ultraviolet dosimeters.

In order to specifically measure the amount of light entering the eye, personal circadian light meter called the
Daysimeter has been developed[11]. This is the first device created to accurately measure and characterize light
(intensity, spectrum, timing, and duration) entering the eye that affects the human body's clock.

The device is a small, head-mounted device which measures an individual's daily rest and activity patterns, as
well as exposure to circadian light—short-wavelength light, particularly natural light from the blue sky—that
stimulates the circadian system. The device measures activity and light together at regular time intervals and
electronically stores and logs its operating temperature. The Daysimeter can gather data for up to 30 days for
analysis[12].

[edit]Energy consumption

Artificial lighting consumes a significant part of all electrical energy consumed worldwide. In homes and offices
from 20 to 50 percent of total energy consumed is due to lighting.[13] Most importantly, for some buildings over
90 percent of lighting energy consumed can be an unnecessary expense through over-illumination.[13] The cost
of that lighting can be substantial. A single 100 W light bulb used just 6 hours a day can cost over $25 per year
to use (.12/kWh). Thus lighting represents a critical component of energy use today, especially in large office
buildings where there are many alternatives for energy usage in lighting. There are several strategies available
to minimize energy requirements in any building:

 Specification of illumination requirements for each given use area.

  Analysis of lighting quality to ensure that adverse components of lighting (for
example, glare or incorrect color spectrum) are not biasing the design.

 Integration of space planning and interior architecture (including choice of

interior surfaces and room geometries) to lighting design.

 Design of time of day use that does not expend unnecessary energy.

 Selection of fixture and lamp types that reflect best available technology
for energy conservation.

 Training of building occupants to use lighting equipment in most efficient

manner.

 Maintenance of lighting systems to minimize energy wastage.

 Use of natural light - some big box stores are being built (ca 2006 on) with
numerous plastic bubble skylights, in many cases completely obviating the
need for interior artificial lighting for many hours of the day.

 Load shedding can help reduce the power requested by individuals to the
main power supply. Load shedding can be done on an individual level, at a
building level, or even at a regional level.
[edit]Health effects

Main articles: Full-spectrum light, Over-illumination, and Light effects on circadian rhythm

It is valuable to provide the correct light intensity and color spectrum for each task or environment. Otherwise,
energy not only could be wasted but over-illumination can lead to adverse health and psychological effects.

Specification of illumination requirements is the basic concept of deciding how much illumination is required
for a given task. Clearly, much less light is required to illuminate a hallway or bathroom compared to that
needed for a word processing work station. Prior to 1970 (and too often even today), a lighting engineer would
simply apply the same level of illumination design to all parts of the building without considering usage.
Generally speaking, the energy expended is proportional to the design illumination level. For example, a
lighting level of 80 footcandles might be chosen for a work environment involving meeting rooms and
conferences, whereas a level of 40 footcandles could be selected for building hallways. If the hallway standard
simply emulates the conference room needs, then twice the amount of energy will be consumed as is needed
for hallways. Unfortunately, most of the lighting standards even today have been specified by industrial groups
who manufacture and sell lighting, so that a historical commercial bias exists in designing most building
lighting, especially for office and industrial settings. Beyond the energy factors being considered, it is important
not to over-design illumination, lest adverse health effects such as headache frequency, stress, and
increased blood pressure be induced by the higher lighting levels. In addition, glare or excess light can
decrease worker efficiency.[14]

Analysis of lighting quality particularly emphasizes use of natural lighting, but also considers spectral content if
artificial light is to be used. Not only will greater reliance on natural light reduce energy consumption, but will
favorably impact human health and performance. New studies have shown that the performance of students is
influenced by the time and duration of daylight in their regular schedules. Designing school facilities to
incorporate the right types of light at the right time of day for the right duration may improve student
performance and well-being. Similarly, designing lighting systems that maximize the right amount of light at the
appropriate time of day for the elderly may help relieve symptoms of Alzheimer's Disease. The human
circadian system is entrained to a 24-hour light-dark pattern that mimics the earth’s natural light/dark pattern.
When those patterns are disrupted, they disrupt the natural circadian cycle. Circadian disruption may lead to
numerous health problems including breast cancer, seasonal affective disorder, delayed sleep phase
syndrome, and other ailments[15][16].

[edit]Environmental issues

Kerosene and whale-oil lamps

In 1849, Dr. Abraham Gesner, a Canadian geologist, devised a method where kerosene could be distilled
from petroleum. Earlier coal-gas methods had been used for lighting since the 1820s, but they were expensive.
Gesner's kerosene was cheap, easy to produce, could be burned in existing lamps, and did not produce an
offensive odor as did most whale oil. It could be stored indefinitely, unlike whale oil, which would eventually
spoil. The American petroleum boom began in the 1850s. By the end of the decade there were 30 kerosene
plants operating in the United States. The cheaper, more efficient fuel began to drive whale oil out of the
market. John D. Rockefeller was most responsible for the commercial success of kerosene. He set up a
network of kerosene distilleries which would later become Standard Oil, thus completely abolishing the need for
whale-oil lamps.[17]

Compact fluorescent lamps

Compact fluorescent lamps (aka 'CFLs') use less power to supply the same amount of light as an incandescent
lamp. Due to the ability to reduce electric consumption, many organizations have undertaken measures to
encourage the adoption of CFLs. Some electric utilities and local governments have subsidized CFLs or
provided them free to customers as a means of reducing electric demand. For a given light output, CFLs use
between one fifth and one quarter of the power of an equivalent incandescent lamp. One of the simplest and
quickest ways for a household or business to become more energy efficient is to adopt CFLs as the main lamp
source, as suggested by the Alliance for Climate Protection

LED lamps
LED lamps have been advocated as the newest and best environmental lighting method.[18] According to the
Energy Saving Trust, LED lamps use only 10% power compared to a standard incandescent bulb, where
compact fluorescent lamps use 20% and energy saving halogen lamps 70%. A downside is still the initial cost,
which is higher than that of compact fluorescent lamps. However, when the life expectancy and other factors
are incorporated, regular LED's are not more costly than CFL lamps. General Electric expects to begin
producing organic LED's for architectural use by 2010.[19]

[edit]Military use

This section requires expansion.

From a military standpoint, lighting is a critical part of the battlefield conditions.[20] Shadows are good places to
hide, while bright areas are more exposed. It is often beneficial to fight with the Sun or other light source behind
you, giving your enemy disturbing visual glare and partially hiding your own movements in backlight. If natural
light is not present searchlightsand flares can be used. However the use of light may disclose your own hidden
position and modern warfare have seen increased use of night vision through the use of infrared
camerasand image intensifiers.

Flares can also be used by the military to mark positions, usually for targeting, but laser-guided
and GPS weapons have eliminated this need for the most part.

[edit]Professional organizations
[edit]International

The International Commission on Illumination (CIE) is an international authority and standard defining
organization on color and lighting. Publishing widely used standard metrics such as various CIE color
spaces and the color rendering index.

The Illuminating Engineering Society of North America (IESNA), in conjunction with organizations
like ANSI and ASHRAE, publishes guidelines, standards, and handbooks that allow categorization of the
illumination needs of different built environments. Manufacturers of lighting equipment publish photometric data
for their products, which defines the distribution of light released by a specific luminaire. This data is typically
expressed in standardized form defined by the IESNA.

The International Association of Lighting Designers (IALD) is an organization which focuses on the
advancement of lighting design education and the recognition of independent professional lighting designers.
Those fully independent designers who meet the requirements for professional membership in the association
typically append the abbreviation IALD to their name.
The Professional Lighting Designers Association (PLDA), formerly known as ELDA is an organisation focusing
on the promotion of the profession of Architectural Lighting Design. They publish a monthly newsletter and
organise different events throughout the world.

The National Council on Qualifications for the Lighting Professions (NCQLP) offers the Lighting Certification
Examination which tests rudimentary lighting design principles. Individuals who pass this exam become
‘Lighting Certified’ and may append the abbreviation LC to their name. This certification process is one of three
national (U.S.) examinations (the others are CLEP and CLMC) in the lighting industry and is open not only to
designers, but to lighting equipment manufacturers, electric utility employees, etc. Generally speaking there is
no legal or practical requirement for the lighting design team to possess the certifications discussed.

The Professional Lighting And Sound Association (PLASA) is a UK-based trade organisation representing the
500+ individual and corporate members drawn from the technical services sector. Its members include
manufacturers and distributors of stage and entertainment lighting, sound, rigging and similar products and
services, and affiliated professionals in the area. They lobby for and represent the interests of the industry at
various levels, interacting with government and regulating bodies and presenting the case for the entertainment
industry. Example subjects of this representation include the ongoing review of radio frequencies (which may or
may not affect the radio bands in which wireless microphones and other devices use) and engaging with the
issues surrounding the introduction of the RoHS (Restriction of Hazardous Substances Directive) regulations.

[edit]National

 World Institute of Lighting and development Corporation

 Association de Concepteurs Eclairage (ACE) in France.

 Associazione Professionisti dell'Illuminazione (APIL) in Italy .

 Hellenic Illumination Committee (HIC) in Greece.

 Indian Society of Lighting Engineers (ISLE)

 Institution of Lighting Engineers (ILE) in United Kingdom.

 Schweizerische Licht Gesellschaft (SLG) in Switzerland.

 Society of Light and Lighting (SLL), part of the Chartered Institution of Building
Services Engineers in United Kingdom.
[edit]See also
 3D computer graphics

 Anglepoise lamp successful and innovative desk lamp design.

 Automotive lighting
  Banning of incandescent lightbulbs

 Bug zapper

 Candlepower

 Domotics computer controlled home lighting.

 Fishing light attractor underwater lights to attract fish

 Hospital lighting

 Light fixture

 Light in school buildings

 Light pollution

 Lighting designer

 Lighting control systems for a buildings or residences.

 Lighting for the elderly

 List of Lighting Design Software

 Luminous efficacy

 Over-illumination

 Seasonal affective disorder

 Stage lighting

 Sustainable lighting

 Three-point lighting technique used in both still photography and in film

 Effect Lighting

 Street lighting
[edit]Inventors

 Joseph Swan, carbonized-thread filament incandescent lamp

 Alexander Nikolayevich Lodygin, carbon-rod filament incandescent lamp

 Nikola Tesla, fluorescent and gas-discharge lamps

 Thomas Edison, long-lasting incandescent lamp with high-resistance filament

 John Richardson Wigham, lighthouse engineer

[edit]Lists
  List of environmental health hazards

 List of light sources

 Timeline of lighting technology

[edit]Footnotes

1. ^ Design Ideas for Chic Spaces at HGTV

2. ^ Field Test DELTA: Post-Top Photovoltaic Pathway Luminaire. Iss. 4.

Lighting Research Center. Online

at: http://www.lrc.rpi.edu/programs/DELTA/pdf/DELTA-Post-

topPhotovoltaic.pdf [last accessed 13 April 2010]

3. ^ Field Test DELTA Snapshot: LED Street Lighting. Iss. 4. Lighting Research
Center. Found online

at: http://www.lrc.rpi.edu/programs/DELTA/pdf/FTDelta_LEDStreetLighting.pd

f [last accessed 13 April 2010]

4. ^ NLPIP Lighting Answers: Photovoltaic Lighting. Volume 9, Issue 3. Lighting

Research Center. Found online

at:http://www.lrc.rpi.edu/programs/nlpip/lightingAnswers/photovoltaic/abstract.

asp [last accessed 13 April 2010]

5. ^ DELTA Snapshot: Outdoor Entry Lighting. Issue 11. Lighting Research

Center. Found online

at: http://www.lrc.rpi.edu/programs/delta/pdf/OutdoorEntry.pdf [last accessed

13 April 2010]

6. ^ Van Derlofske, J, JD Bullough, J Watkinson. 2005. Spectral Effects of LED

Forward Lighting. TLA 2005-02. Lighting Research Center. Found online

at:http://www.lrc.rpi.edu/programs/transportation/TLA/pdf/TLA-2005-02.pdf [la

st accessed 13 April 2010]

7. ^ Light bulbs — Don’t be Dim. Light up your Life!, David Vernon

8. ^ Another view of the interior by Panini (1735), Liechenstein Museum, Vienna

9. ^ ASSIST recommends: Guide to Light and Color in Retail Merchandising.

2010. Volume 8, Issue 1. Available online

at:http://www.lrc.rpi.edu/programs/solidstate/assist/recommends/lightcolor.as

p
 10. ^ ASSIST recommends: Recommendations for Specifying Color Properties of
Light Sources for Retail Merchandising. 2010. Volume 8, Issue 2. Available

online

at:http://www.lrc.rpi.edu/programs/solidstate/assist/recommends/lightcolor.as

11. ^ Rea MS, Bierman A, Figueiro MG, Bullough JD. 2008. A New Approach to
Understanding the Impact of Circadian Disruption on Human Health. Journal

of Circadian Rhythms, 6:7 (29 May 2008). Found online

at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430544/ [last accessed 13

April 2010]

12. ^ Lighting Research Center Website: New approach sheds light on ways
circadian disruption affects human health. Found online

at:http://www.lrc.rpi.edu/programs/lightHealth/projects/CircadianHealth.asp?

id=167 [last accessed 13 April 2010]

13. ^ a b Hawken, Paul; Lovins, Amory; Lovins, L. Hunter (2000). Natural

Capitalism. Back Bay Press, Time Warner Book Group. ISBN 0-316-35300-0

14. ^ DiLouie, Craig (2006). Advanced Lighting Controls: Energy Savings,

Productivity, Technology and Applications. The Fairmont Press, Inc.. ISBN 0-

88173-510-8

15. ^ Figueiro MG, Rea MS (February 2010). "Lack of short-wavelength light

during the school day delays dim light melatonin onset (DLMO) in middle

school students". Neuro Endocrinology Letters 31 (1):4. PMID 20150866.

16. ^ Figueiro MG, Rea MS, Bullough JD (2006). "Does architectural lighting
contribute to breast cancer?". Journal of Carcinogenesis 5: 20.

doi:10.1186/1477-3163-5-20. PMID 16901343.

17. ^ Robbins, James S.. "How Capitalism Saved the Whales". The Foundation
for Economic Education.

18. ^ Time:Bright Idea

19. ^ "GE Shows How to Roll Out OLEDs".

20. ^ Sun Tzu, The Art of War

[edit]Sources
  Lindsey, Jack L. (1991). Applied Illumination Engineering. Lilburn, Georgia:

The Fairmont Press, Inc.. ISBN 0-88173-060-2.

 Fetters, John L (1997). The Handbook of Lighting Surveys & Audits. CRC

Press. ISBN 0-8493-9972-6.

 Guo, Xin; Houser, Kevin W. (2004). "A review of colour rendering indices and

their application to commercial light sources". Lighting Research and

Technology 36 (3): 183–199.doi:10.1191/1365782804li112oa

[edit]External links

Wikimedia Commons has

media related to: Lighting

 Illuminating Engineering Society of North America official Web site

 ENLIGHTER.ORG online Lighting Design magazine

 IESNA Advanced Lighting Guidelines

 Lighting Research Center @ Rensselaer Polytechnic Institute

 Shedding Light on Home Lighting Use by Lyle Tribwell (Home Energy

magazine online)
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Lamps and lighting

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Mercury-vapor · Hydrargyrum medium-arc iodide (HMI) · Hydrargyrum quartz iodide (HQI) · Metal halide (Ceramic) · Sodium vapor
discharge (HID)

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Electric arc Carbon arc · Yablochkov candle

Combustion Acetylene/Carbide · Argand · Candle · Diya · Gas · Kerosene · Lantern · Limelight · Oil · Safety · Rushlight · Tilley · Torch
 Other Light-emitting diode (LED) · LED lamp · Solid-state (SSL) · Plasma · Electroluminescent wire · Chemiluminescence · Radioluminesce

Categories: Lighting | Garden features | Architectural elements

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