Glossary of Lighting Terms You May
- A -
The most common incandescent household lamp; a standard general service
Localized and directional lighting used to highlight, focus attention
or dramatize a room or outdoor space. As part of a decorating scheme,
it is used to spotlight paintings, houseplants and other possessions,
or to highlight the texture of a wall, drapery or outside landscaping.
Accent lighting requires at least three times as much light on the focal
point as the general lighting around it.
ADA Wall Brackets
Wall-mounted fixtures that extend less than 4” from the wall comply
with the Americans with Disabilities Act and are usually called ADA brackets.
Adjustables are accent lights that can be aimed. The professional term
is “adjustable accent light.” In practice, most of the fixtures
used for accent lighting are adjustable in some fashion.
How you point or direct an adjustable light. The aiming angle is calculated
from vertical or nadir. An aiming angle of 30 degrees is effective for
paintings and/or sculptures.
Shades can be made of either alabaster stone or alabaster glass. Alabaster
stone is much like marble in that it is quarried, cut and made into shades
and bowls. It creates a warm, rich look, with each piece being completely
unique. Stone is very expensive, however, so many lighting pieces recreate
the look with more affordable alabaster glass.
The trade name used for a method of anodizing. Now a generic term for
brightened, anodized aluminum.
Alternating Current (AC)
Flow of electricity which cycles or alternates direction many times per
second. The number of cycles is referred to as frequency. Most common
frequency used in this country is 60 Hertz (cycles per second).
A pure metal, aluminum can be shaped and finished easily. It can be dyed
to a brass-like finish, but without the depth and luster of real brass.
Aluminum is usually sealed through painting or anodizing to avoid oxidation.
Also known as general lighting, ambient lighting provides an area with
overall, non-specific illumination. Ambient lighting radiates a comfortable
level of brightness, enabling one to see and walk about safely. It can
be accomplished with chandeliers, ceiling or wall-mounted fixtures, recessed
or track lighting or with outdoor fixtures. A basic form of lighting that
replaces sunlight, ambient lighting is fundamental to lighting a home.
Amperes / amps
The unit of measurement of electrical current.
A finish that simulates aging, often accomplished by wiping dark pigment
across a metal or wooden part.
Opening of a fixture through which light exists.
This broad term generally refers to built-in fixtures, such as downlighting,
valance lighting or a luminous ceiling. Some people also include functional
lighting, such as track or simple fluorescent, which has an architectural
Inert gas used in incandescent and fluorescent lamps. In incandescents,
argon helps retard the evaporation of the tungsten filament.
A mainstream design style that reached its heyday in the 1920s. Typified
by streamlined design shapes, geometric patterns, bold outlines and the
artistic use of industrial materials, such as stainless steel, plastic
and pressed glass.
A decorative art movement that emerged in the late nineteenth century.
Characterized by dense asymmetrical ornamentation in sinuous forms.
Average Rated Life
The number of hours required for half of a large group of lamps to fail
or burn out. The actual life of any lamp or small group of lamps will
typically be different from the average rated life.
- B -
Part of the fixture that blocks light to prevent glare and control brightness.
Baffles may be integral blades, plates or grooves or an accessory. Baffles
are often painted black to absorb light.
Electrical or electronic component required for fluorescent (and HID)
lamps. Ballasts provide enough voltage to start the lamp and then limit
the current for continuing operation.
A desk or table lamp, usually in a traditional style, that has a rectangular
cased glass or metal shade. So-called because they were common fixtures
in banks in the first half of the 20th century.
The end of the lamp that inserts into a lamp socket. The end or ends of
a lamp that makes electrical and mounting connections.
Bath or vanity lighting refers to fixtures used to light the mirror in
a bathroom. A bath strip is a long fixture that mounts along the top or
sides of the mirror. Also see “bathbar lighting.”
These fixtures supply task lighting, while supplementing the general lighting
provided by ceiling fixtures. Similar to lighting in theater dressing
rooms, these softly glowing lights are most often arranged in a row /
bar fashion to provide excellent lighting for shaving and grooming.
Clear glass, often with a high lead content, with edges that are cut on
an angle to add depth and glitter.
Move the airflow in a ceiling or desktop fan. Blades are made of plywood,
laminated woods or plastic.
Irons that hold a ceiling fan’s blades.
Angle of the blade iron or blade holder on a ceiling fan. Fans with a
higher degree of blade pitch will move more air.
Hand blown glass is created by artisans who blow air into a molten balloon
of glass. The artisan’s skill determines the shape and texture of
the finished piece.
The saucer at the base of a candle originally designed to catch the molten
wax drippings of the candle. Used on chandeliers, sconces, etc.
Lights mounted on short, heavy piers or posts. They are used mostly for
larger residences and campus settings.
Glass elements held together by metal strips, typically brass or copper;
includes Leaded Glass, which has a heavier look.
An alloy of zinc and copper, brass forms and polishes easily. Solid brass
means the fixture is made entirely of brass, rather than a brass-plated
Harder than brass, bronze is used for its durability, especially in high-grade
Satin or lightly textured finish, usually on metal, produced by brushing
with a wire wheel or buffing with a fine abrasive.
Built-in lighting generally refers to lighting equipment mounted into
coves and cornices, behind valences, or integrated into furnituire and
The everyday term for an incandescent lamp. Also refers to the outer glass
envelope of the lamp.
- C -
Multiple wires arranged in a common covering of insulating plastic or
other materials, used as an electrical conductor.
Glass consisting of a layer of clear glass fused to a layer of opal or
other tinted glass. Cased glass transmits light more efficiently than
opal, with more luster and better diffusion. Cased glass can be blown
The unit of measurement of luminous intensity of a light source in a given
Luminous intensity of a particular light source expressed in candlea.
A fixture that has a tall, slim column, taken after traditional candlestick
lighting. Also known as a console lamp.
Fixture part that covers an outlet box.
Another term for recessed downlights.
Pouring or forcing metal or glass into a prepared mold or any part manufactured
in this manner.
Provide general lighting. They are practical in busy areas such as foyers,
hallways, bedrooms, kitchens, baths, laundry rooms and dens. They are
available with incandescent, fluorescent and energy-efficient compact
Ceiling fans consist of (from top to bottom) a canopy with hanger ball,
a down rod, the motor, blades, and light kit.
Tool with jaws that open as you squeeze the handles together. Used to
pry open links of chain to change the suspension height of a chandelier
or other fixture.
General lighting fixtures that can provide sparkle and style to rooms
and entryways. They are also used in bedrooms, foyers, over a living room
furniture grouping, or over a piano. Some are designed with downlights
or use shades to provide task lighting for homework, reading or cooking.
Chandeliers are available in both incandescent and tungsten-halogen models.
The addition of a dimmer control allows you to alter the intensity of
the light to suit your mood or time of day.
In dimming controls, a group of fixtures that are operated together, generally
of the same type or for the same function.
A blown glass tube of various shapes placed around flame to protect it
against wind. In today’s usage, it is for ornamentation and light
Chrome takes a high, lustrous finish. A softly brushed chrome finish simulates
stainless steel, but without the durability and depth.
Wiring path for electricity, including conductors, load and circuit protection.
Resettable safety device to prevent current flow or prevent excess current
Piece that is used to clip a shade onto a light bulb.
Reminiscent of pre-revolutionary America, this style emphasizes clean,
simple lines, though it may also refer to a more ornate style which relies
on curving lines and scroll work.
The appearance of white light in terms of warmth or coolness.
Small recessed incandescent fixtures generally five inches deep.
A small fluorescent lamp that is often used as an alternative to incandescent
lighting. The lamp life is about ten times longer than incandescent lamps
and is 3 to 4 times brighter. Also referred to as PLI DL, CFL or BIAX
Lighting derived from the industrial styling of Modernism, blending function
and form. Brushed metal surfaces, the use of plastic materials, sleek,
streamlined forms, and geometrically shaped glass shades and bowls predominate.
A soft, pure metal, usually used for accent detailing. It oxidizes to
a distinctive green color when exposed to the air.
Light built into a cove, a shelf or ledge at the upper part of a wall,
to illuminate the ceiling. Typically fluorescent, cold cathode or low
Fine quality transparent glass. May be used in table lamps, chandeliers
and floor lamps in a variety of styles and cuts. See also Lead Crystal.
Outdoor fixture, which can be mounted to a wall or an overhang to aim
light directly on paths and porches.
- D -
UL listing for fixtures used in a moist unexposed area, such as a bathroom
or porch area.
Deck lights typically mount to the outside of a home or to the railing
of a wooden deck. Since they are located near where people sit, good shielding
and proper mounting height are important to reduce glare.
Decorative Bulbs (D)
General service bulbs available in a variety of wattages and shapes. Decorative
bulbs include flame, teardrop and candelabra shapes, among many others.
Decorative fixtures help establish the tone and style of a room. Decorative
fixtures are meant to be seen, which means their brightness should be
kept low enough to avoid glare.
Film that reflects visible light and transmits infrared light. Reflector
lamps with dichroic coatings, such as most MR16s provide a cooler beam
because most of the heat goes out the back. Dichroic PAR lamps are often
called “cool beam.”
Casting in a reusable mold (the die). Die-casting are generally precisely
manufactured parts requiring a high initial investment in the die.
Light control device that spreads light by scattering it. Opal glass and
plastic, etched glass, fabric and paper shades act as diffusers.
Control that varies the output of the light source by reducing the voltage
or current to the lamp.
Lighting that casts all, or at least 90%, of its light downward. The term
can also refer to the distribution of light or the fixtures that produce
this type of lighting. With intense beams, direct lighting is very dramatic,
rendering forms and textures well. Typical fixtures include recessed lights,
track lights, some pendant lights and task lights.
Light comes from up and down. This light is well balanced and pleasing.
Light that is predominately direct is also called”semi-direct.”
Typical fixtures include most pendant lights, wall brackets and wall valances.
Uses include task/ambient lighting over tables and in hallways.
Downlights usually refer to recessed downlights. However, some designers
use the term to describe any fixture aiming straight down.
Direct-mounted fixtures are typically bowls that are fastened to a ceiling
holder. Most use diffusers of glass or acrylic. Beveled glass is also
popular. These fixtures work best for low to moderate light levels.
Dual Mounting System
On ceiling fan units. This system enables you to mount a fan on a down-rod
or flush to the ceiling.
- E -
A style of interior decorating that mixes different styles and period
of lighting and furniture.
Lights at the entry of a home that help guide visitors and provide security.
These pieces can also be used to light breezeways.
Ellipsoidal reflector lamp is a soft glass lamp that focuses the beam
about two inches in front of the bulb. It is designed to improve the efficiency
of deep baffle recessed downlights, but is often misused in residential
applications, where it may stick down from the fixture.
Glass treated by an acid bath, producing a satiny, diffused surface or
Extended Life Lamp
Incandescent lamp with 2500+ hours of rated average life and reduced output;
uses a stronger filament.
A recessed, adjustable accent light that protrudes slightly below the
Used to adapt a fan to high ceilings, lowering the fan from the ceiling.
Piece used to make height adjustments for the shade on the harp.
- F -
Side of a prism, seen most often in crystal glass chandeliers and other
Fan Blade Screws
On a ceiling fan, screws that hold the blade irons to the blades.
Plaster and other material can be molded and textured or finished to look
like real stone. Genuine stone is usually too heavy for the body of a
light fixture, but is popular for the bases of portable lamps, where weight
is an advantage.
A staple of Art Deco design and lighting. From this period most figure
lamps portray a female figure, often holding a globe shade. Victorian
figure lamps often involve cherubs or young maidens. Animal and Cartoon
figures in children’s lighting are more modern examples.
The tightly coiled tungsten wire of an incandescent lamp; glows to produce
light when electricity flows through it.
In incandescent lamps, usually argon or krypton with trace nitrogen. In
fluorescent lamps may be argon. Halogen is used in halogen incandescent
Screws in the top of the harp to keep a shade secure on a lamp, and also
serves a decorative purpose.
Part of a fixture that accepts a glass or plastic globe. The diameter
of the fitter determines the size of the neck or opening in the globe.
Fixtures are described by their mounting and lighting qualities. Types
include chandeliers and lanterns, diffusing and shaded pendants, wall-mounted
lighting, close-to-ceiling fixtures, outdoor fixtures, portables and ceiling
The wide distribution of a reflectorized lamp, abbreviated FL. Also a
fixture with a widespread light throw.
Floodlights create a widespread distribution of light, perfect for illuminating
a wall, sign or large object. A floodlight should be well shielded with
an accessory louver or shield to avoid stray light and glare. You can
plants to block unwanted light.
Lamps which operate by creating an electric arc inside a gas-filled tube.
The color of the light is determined by the type of phosphor coating used
in the lamp.
Recessed fluorescent fixtures for 2 foot and 4 foot lamps, generally in
modular sizes; used commercially.
A type of ceiling fan that mounts directly to a junction box, and do not
have a down-rod to maintain maximum clearance from the floor.
Unit of illuminance (light falling on a surface). One lumen falling on
one square foot equals one-foot candle. Also, a measurement of the amount
of light reaching a subject.
Part of a recessed downlight connected to the electrical circuit and generally
installed when the ceiling is open. The electrified mounting form or housing
which supports the optical assembly of a recessed fixture. Frame-In Kits
are of various types according to the nature of the construction and the
Fixture with lens and shutters, creating an adjustable, sharp-edged beam
to outline pictures and other objects.
The French country style relies on the warm tones of the Provencal countryside,
golden yellows, pure blues and deep reds. Lamp materials can be in wrought
iron or antique finishes and the rooster theme is seen frequently.
- G -
Globe-shaped incandescent, generally for exposed use.
Also known as ambient lighting, general lighting provides an area with
overall, non-specific illumination. General lighting radiates a comfortable
level of brightness, enabling one to see and walk about safely. It can
be accomplished with chandeliers, ceiling or wall-mounted fixtures, recessed
or track lighting or with outdoor fixtures. A basic form of lighting that
replaces sunlight, general lighting is fundamental to lighting a home.
General Diffuse Lighting
General illumination from light cast evenly in all directions. Typical
fixtures include pendant globes, chandeliers, and some table lamps.
General Service (A) Bulbs
General service bulbs are inexpensive and are readily available in a variety
of wattages and shapes. They produce a yellowish white light that is emitted
in all directions. Available in either clear or frosted versions.
An adjustable ring that holds the PAR or MR lamp by its rim. A gimbal
ring track fixture has no housing.
Bright lighting that causes discomfort and impairs good visibility. Possible
causes may be light sources that are too bright for the application, or
fixtures that may not conceal bulbs sufficiently, among many others.
Directional light at an acute angle, which emphasized texture. The sources
of grazing light must be close to the surface. See also Wall Grazing.
On a ceiling fan, the lower part of the housing, which has many different
Connecting electrical components to earth for safety.
- H -
Hall / Foyer Fixtures
Can create a welcoming atmosphere, while providing you with general ambient
lighting. Use ceiling, chain-hung or close to ceiling flush-mount fixtures
for lighting in hallways, stairways and entrance halls.
Incandescent lamp with halogen gas fill and a quartz glass capsule. The
quartz capsule requires a separate glass shield or enclosure. Due to the
halogen cycle, halogen lamps operate at higher internal temperatures,
producing more lumens per watt and brighter light than ordinary incandescent;
lamp life is also extended. Halogen lamps include A, MB, T, PAR and MR
Glass seen most commonly on outdoor fixtures that has a rippled, pitted
“hammered” antique look.
Individually produced glass made by artisans who blow molten glass into
different decorative shapes.
Used to attach a shade onto a lamp.
A shade that is lined with plastic.
Like recessed downlights, surface mounted fixtures must pass heat tests
to assure they do not affect combustible ceiling materials. This limits
the maximum wattage in these fixtures, and sometimes necessitates the
installation of high-temperature wiring. Always follow the labeled lamping;
never use higher wattages or different lamps.
A threaded pipe coupling with a side opening used in wiring a luminarie
and for attaching a fixture to an outlet box.
Main body of a ceiling fan that connects the motor and other components.
On a ceiling fan, another name for “Switch Housing.”
Lower part of the switch housing on a ceiling fan hub. On some fans this
part is removable.
A lamp having a distinctive globe glass housing for its bulb. Patterned
after 19th century oil and candlestick lamps.
- I -
Insulated Ceiling Fixture. Recessed downlight suitable for direct burial
in thermal insulation. Called type IC.
These outdoor accent lights provide maximum concealment because the source
is recessed into the ground. Both line and low voltage sources are available.
Light produced by heating material so it glows. Incandescent filament
lamps, candle flames and glowing coals are all examples.
Produces light with a wire filament, which create light as it is heated
by electric current.
Lighting that directs all or most light upward for ambient or general
illumination; comfortable illumination with few shadows. Typical fixtures
include uplight cans, fluorescent lighting aimed up, track lights aimed
up and torchieres.
Inside Frosted Lamp
Incandescent A lamp with a light etching or sprayed on diffusing coating
on the inside of the bulb. Designated as IF.
Insulated Ceiling Fixture
Recessed down-lighting suitable for direct burial in ceiling thermal insulation.
Called Type IC.
Integrated Dimming Systems
A dimming switch that allows you to create multiple preset lighting scenes
within a room. Scenes can be recalled at the touch of a button from a
single wall box or with a hand held remote control.
On ceiling fans, a two-wire computerized system with wall control convenience
that gives independent control of lights and fan. It has a silent multi-speed
operation for the fan and provides variable light intensity.
Infrared-Reflecting Halogen Lamp. A special interior coating redirects
infrared energy onto the filament, which increases output without added
A strong metal, iron imparts a natural quality to a lighting fixture.
Wrought Iron is heated and hammered into shape, and can be formed into
pleasingly fluid forms.
- J -
Plug-in stem used in low voltage fixtures.
Enclosure that protects spliced wires and supports surface fixtures, such
as wall fixtures or ceiling fans. Also called an outlet box.
- K -
Scientific unit of temperature. Color temperature is measured on the Kelvin
KWH. A unit of measurement for electrical energy. One kilowatt hour equals
1000 watts of energy used for one hour.
- L -
Clear coating that protects metal fixtures from rusting or tarnishing.
May be tinted in various colors by adding colored dye.
A portable lamp consists of a (from bottom to top) a stand, a base, a
mount through which the electrical wiring travels, a neck, a socket to
hold the bulb, a lamp shade, a harp that connects the top of the shade
to the socket, and a decorative finial that holds the harp in place.
Socket inside a housing, which holds the lamp in place and connects it
to the electrical source.
Equipping a fixture with a lamp.
Unlike chandeliers which are oriented radially, lanterns hang vertically,
often with several tiers. Modern pendant lanterns use hanging glass panels
or glass rods, often with beveled edges to reflect the light.
Fine quality glass having a high content of lead oxide.
Small pieces of glass joined at the edges with metal, traditionally lead.
Light Emitting Diode. A small, solid state device used to indicate dimmer
or control status; also used in signs and control units.
Devices which give you flexibility, decorative effects and multiple uses
from your lighting sources. Today’s sophisticated dimming systems
enable you to lower the light level to conserve energy and increase bulb
life; vary the mood of a room; alter light source intensity; create lighting
scene in each room. Types of controls include integrated dimming systems,
touch dimmers, slide dimmers and rotary dimmers.
Pattern of light produced by a fixture, or created in a room.
The performance of any light fixture depends on the light source, or bulb,
that’s used. Different sources produce different effects.
Line Voltage Systems
120 volt distribution is used mostly for lighting mounted to the outside
of a house or for post-top lanterns along a drive or path. Line voltage
landscape lighting can provide more light and handle greater distances
than low voltage systems, but the installation is less flexible and more
Low Voltage Fixtures
Recessed track, task, decorative or landscape fixtures for low voltage
lamps. A transformer is required for these fixtures and may by integrated,
local or remote.
Low Voltage Housing
Recessed housing with an integral, or occasionally, remote transformer.
Low Voltage Lamps
Incandescent lamps that operate at 6, 12 or 24 volts. Low voltage lamps
require a step-down transformer to reduce the voltage from the normal
household 120 volts.
Low Voltage Lighting System
A type of lighting that operates on 12-volt current rather than the standard
120 volts. Power is supplied by a transformer, which is itself connected
to 120-volt power.
Low Voltage Trim
Either a reflector trim with an integral transformer, which installs in
a standard housing, or the dedicated trim to a low voltage housing.
Low Voltage Track
Track powered at low voltage by a step-down transformer, which installs
in a standard housing; or the dedicated trim to low voltage housing.
The amount of light that a bulb produces. Unit of output; technically
- M -
Machine Blown Glass
Glass shaped by mechanically forcing air into molten glass so that it
takes the shape of a mold.
Lamp or fixture surface finish producing a diffuse, lightly textured dull
Along with the Arts And Crafts movement, Mission style became popular
at the turn of the 20th century. The emphasis is on simplicity, straight
lines, geometric shapes and handcrafted pieces. Ornamentation may be from
wrought iron, brass and woods, especially oak.
Base used on high-wattage incandescent and HID lamps.
Control that uses passive infrared or ultrasonic detection to sense whether
someone is present or not, and to turn a light on or off appropriately.
Commonly used in outdoor flood or spot fixtures. “Automatic On”
sensors turn lights on when presence; “Manual On” sensors
require you to press a switch. Both types turn lights off automatically
when they no longer sense a presence.
In a ceiling fan, screws that hold the fan blades and flywheel.
Multi-facet reflector lamp, of which the most popular is MR16. MR lamps
surround a halogen capsule with a computer-designed glass, or metal reflector
with many surfaces or facets. These compact lamps require a glass cover,
either integral or with the fixture.
- N -
National Electrical Code
Sets out standards for wiring and electrical devices. The NEC requirements
are widely followed by local jurisdictions.
National Electrical Manufacturers Association. Includes lamp, electrical
device and larger fixture manufacturers. NEMA develops consensus ratings
and designations for various products.
Low pressure arc discharge lamps that operate at high voltage. Used for
decoration and signage purposes.
A system of dimming controls that are wired and programmed to respond
together, usually to link controls in several rooms.
The power rating of lamps, as published by lamp manufacturers.
- O -
Milky, translucent glass produced by adding ingredients to clear glass.
Used for diffusing light.
Classic lighting is the popular paper lantern or shade style. Chinese
and Japanese motifs may also be used to decorate table and floor lamps.
Any hard wired, low-voltage or solar powered lighting system that is used
in an exterior space. Outdoor lighting can enhance the beauty of your
home, making it safer and more secure. Outdoor lighting typically is an
investment that pays off in the value it adds to a home.
Also Junction Box. Enclosure that protects spliced wires and supports
Incandescent lamps experience shortened lamp life when operated above
their rated voltage.
- P -
Parabolic Reflector Bulbs (PAR)
Bulbs used to control the level of light more precisely. They provide
about four times the light of General Service (A) bulbs and are used in
recessed and track lighting. Weatherproof casings make them suitable for
outdoor spot and flood lighting fixtures.
Parabolic Aluminized Reflector Lamp. Constructed of hard glass with a
separate back reflector and front legs that are fused together. PAR lamps
may be line or low voltage and can be used unprotected outdoors.
Pavers are luminous elements mounted in the ground of a patio or pathway.
They act like lighted paving stones, marking a path. Some pavers are designed
to replace individual bricks, others are imbedded in concrete.
Pendants can provide both general and task lighting. With shades or globes
to avoid glare, they can be suspended from the ceiling over dinette table,
kitchen counters or work areas. When used over end or night tables they
free up space normally occupied by table lamps. The addition of a dimmer
control allows you to alter the intensity of the light to suit your mood
or time of day.
Pendant mount on a chain, stem, cable or wire, and hand down into space.
The word also refers to a style of hanging fixture with a single, central
luminous element (like a cone, globe or dish), distinguished from a chandelier,
which typically has several arms or luminous elements.
Light-sensitive device used to operate fixtures according to available
daylight. They are used in solar lighting and to turn outdoor or security
lights on and off at dusk and dawn.
Recessed downlight that includes a faceplate with a small aperture used
for inconspicuous accent lights.
The space between the ceiling and the floor or roof above.
Portables, typically table or floor lamps, include a cord and plug. They
are distinguished from fixtures, which are permanently fastened and electrified.
Portables include table lamps, floor lamps and torchieres. Small specialty
lamps, such as clip-on lights, can lights, adjustable task lights, desk
and piano lights also classify as portable lamps.
Outdoor fixtures used to mark the entrance to a property, define a driveway
or light a garden pathway.
The connection point that brings electricity to track and other lighting
systems. Power feed may be at the end, floating or at a wiring intersection.
Refractor of transparent glass or plastic, with three or more straight
sides. Light entering one side of the prism bends and exits the other
Recessed downlight with a retractable lamp-holder/housing (usually a round-back
cylinder or bullet) that pulls down from the ceiling at angles up to 90
degrees from vertical.
- Q -
Single-ended compact fluorescent lamp consisting of two twin tubes on
a single base.
Or quartz halogen. Term derives from the quartz glass that encloses the
filament and halogen gas. Quartz glass can withstand the high pressure
of the halogen lamp, but it transmits more UV radiation than ordinary
hard glass. Touching the quartz glass with bare hands leaves an oily residue
that greatly reduces lamp life.
- R -
Reflector Lamp. Soft-glass reflectorized lamp with a generally smooth
Rated Lamp Life
The point in hours where 50% of a lamp type initially started will still
A fixture mounted in the ceiling. With downlights, only the aperture and
trim are visible from below. With fluorescent troffers and luminous ceilings,
only the light shield is visible. Recessed fixtures provide direct downlighting
and are highly effective used as wall washers, to accent painting, or
to highlight architectural or home décor points of interest.
Recessed Lighting is installed above the ceiling. Only the aperture or
opening of the light shows. Recessed downlights are the most popular form
of architectural lighting fixture because they blend into almost any décor
and provide a range of lighting effects.
A piece of material with a reflective surface that directs light in a
desired direction. Reflectors are frequently specular, but may also be
glossy, diffuse or matte.
A light source of incandescent, compact fluorescent or HID source with
a built in reflecting surface, usually a silver or aluminum coating on
A project where the existing lighting fixtures in a home or office setting
are cleaned and new lamps installed.
Electronic control mounted separately from the master or individual dimmer,
permitting operation from multiple locations. Full-function remotes set
the dimming level, as well as switching on/off.
Upgrading a fixture, room or building by installing new lighting fixtures,
parts or equipment.
On a ceiling fan, a switch that reverses the blade direction and airflow.
Raises a shade 1/2 inch to 2 inches for decorative appearance. Used instead
of a layer harp.
A cable comprised of flexible plastic sheathing inside of which are two
or more insulated wires for carrying electricity.
A dimming control that provides full-range, manual control of a light
source. Some are equipped with a push-button operation that allows you
to turn the light on and off and return to the previous lighting level.
Process of wiring a home and installing rough-in sections of the fixtures
and the back boxes of electrical devices; precedes the finish work.
Rough Service Lamps
Incandescent lamps designed with extra filament supports to withstand
bumps, shocks and vibrations.
Corrosion of metal, particularly iron and steel, from exposure to moist
air and other elements; also called oxidation. Rust is a reddish-brown
finish that can be produced by a paint or chemical process.
- S -
A process where molten metal is poured into a mold of compacted sand.
The molds can only be used once. The process is costly, including finishing
the fairly rough casting.
Slightly textured or brushed surface having a fine grain that reflects
light with some diffusion.
The arch or scallop-shaped pattern on a light fixture.
Specific setting for a group of dimmers channels or zone. A multi-scene
control allows you to select the different setting by pushing a button.
Wall bracket fixture derived from the form of a candelabra, often with
exposed or decorative light sources.
An opaque or translucent covering on luminaries and portable lamps to
shield the light source. Redirects the light and enhances decoration.
Measure in this order: Top across, bottom across, slant of the sides,
Accent lighting technique that creates a dramatic outline by back lighting.
Also used in landscape lighting.
Slide dimmers operate via a slide toggle, providing a full-range of manual
dimming control. Some are equipped with a touch-button that allows you
to return to the previous lighting level. Others have an indicator light
that glows in the dark for easy location.
The flexibility of track lighting can be a major help when trying to light
from a sloped ceiling. Most recessed fixtures cannot be aimed to light
art on an adjacent wall, while track lighting fixtures allow you to do
In architecture, the underside of an overhead component, such as an arch,
cornice, beam or balcony. Often used to describe an area of the ceiling
that drops below the primary surface.
Soft or Lined Shade
Shade that is lined with fabric.
Incandescent lamp with a dense, milky-white silica coating on the inside
of the bulb. Diffuses the light and completely conceals the light filament.
Fixture or parts made entirely of brass, not plated or simulated. Solid
brass parts are “solid brass”, not “solid parts.”
Often they are hollow castings or tubing.
Electronics that use semi-conductor chips and circuitry.
This style evolved from furnishings used in the rural Southwestern United
States, particularly in Santa Fe. Lighting fixtures feature simple forms
and lines with terra cotta finishes and animal or regional motifs.
A broad term referring to everything from line and low voltage strip lights
to special display or controlled lighting as seen in retail and commercial
Highly polished and mirror-like. Semi-specular finish is generally bright,
but without a well-defined mirror image.
The cross frame near the top of a shade.
The process of shaping a disk of metal by rotating it on a lathe and pushing
it with a forming tool. Also, a part made this way.
Reflectorized lamp with a narrow light distribution.
Short for recessed square downlights, which are usually shallow fixtures
with diffusers or lenses.
Stainless steel resists corrosion and has a rich, deep luster. It is particularly
used in bathroom and kitchen settings for a clean, contemporary look.
Inexpensive way to form sheet metal by hitting it with a die.
Step Lights are recessed into walls and stairs so they illuminate the
treads of stairs or pathways. An eye shield is often used to block direct
view of the light source.
Crystal of the ultimate chemical purity, saturated with more than 30%
lead oxide, cut and polished with ultimate precision by a machine. This
is the finest crystal available and also the most expensive.
Surface-mounted fixtures are also know as ceiling mounted fixtures. They
attach directly or close to the ceiling. The light distribution is often
semi-direct or general diffuse.
Material or chain hanging in a decorative fashion between two points.
A table or wall mounted lamp that uses a moveable horizontal arm, allowing
it to be positioned any number of ways.
Wiring that connects the switch or dimmer output to the fixture or load
- T -
Tubular Lamp; may be incandescent, halogen or fluorescent.
Lighting directed to a specific area or surface that provides illumination
for visual tasks, such as reading, sewing or cooking. It can be provided
by recessed and track lighting, portable lighting or pendant lamps. Task
lighting should be free of distracting glare and should be bright enough
to prevent eyestrain.
Dimmer that works with a three-way switch for control from two locations;
turns on/off and dims at the dimmer, but only turns on/off at the switch.
Incandescent lamp with two filaments that provides three levels of light
when sequentially switched.
Operates a fixture from two locations. Also called a three-pole switch.
Also called a “three-pole switch” because it is connected
to three wires; “hot” in, “switched” out and a
“traveler” to the other three-way switch.
Based on original designs by American Louis Comfort Tiffany, Tiffany lighting
relies on cut stained glass and ornately detailed bases, often in bronze.
Tiffany was heavily influenced by Japanese art forms in which nature was
front and center.
The upward inclination of a light source from a level horizontal position.
Device that turns lights on and off at pre-programmed times.
Tinted glass is clear glass with a pigment or color added. This produces
color throughout the piece, which will not chip or peel. Also clear or
opal glass with a thin film of colored glass or plastic coating.
Lever used for control as in the common toggle switch or toggle dimmer.
Indirect floor lamp that sends all, or most, of its light upward.
Part that joins sections of electrified track.
Any lighting system that utilizes individual lamps or lamp housing which
operate off a track or strip mounted to the wall or ceiling. Track lighting
can provide general, task or accent lighting all at once in a very flexible
system. You can move, swivel, rotate and aim the individual fixtures in
any direction along the track, giving you the flexibility to change your
lighting scheme as the need arises. You can also hang chandelier and pendant
lighting fixtures from some types of track.
A device used to raise (step up) or lower (step down) the electric voltage.
For example, many halogen ceiling fixtures require a transformer, most
commonly hidden in the wall during installation, to function properly.
Step down transformers reduce household voltage (120 volts) to low voltage
used in accent and landscape lighting. Larger transformers reduce high
voltage used for efficient power distribution to safe and flexible household
voltage. Input voltage is on the primary tap; output voltage on the secondary
Sometimes the edge or visible part of a recessed downlight; as in “white
trim”. Sometimes the finishing section of the recessed fiture; as
in “housing and trim.”
Recessed fluorescent fixture for use in a suspended ceiling; derived from
the words “trough” and “coffer.”
A gas filled tungsten incandescent lamp containing a certain amount of
halogens that intensifies the light source. More commonly referred to
as “Halogen” lighting.
- U -
Linear, double-ended fluorescent lamp, usually T8 or T12, bent into a
Fixtures which are placed under a cabinet or room recess to provide task
and accent lighting. Under kitchen cabinets they can light a countertop
with task lighting. In a display cabinet they can be used to illuminate
a prized collection. They include slim, energy-efficient fluorescents,
miniature track lighting and strips of low-voltage mini-lights.
Underwriters Laboratory. Commonly referred to as “UL”. An
independent organization whose responsibilities include rigorous testing
of electrical products. When products pass these tests, they can be labeled
and advertised as “UL Listed”. UL tests for product safety
Ultraviolet Light (UV)
Light that is shorter in wavelength and higher in frequency than visible
Common name for a plain track that accepts a wide range of line voltage
Wall bracket light fixture with an uplight distribution and a distinctive
Commonly refers to ceiling and wall fixture lighting that is plain and
durable. Utility fixtures usually feature plastic lenses and and diffusers
instead of glass. The housing may also be of molded plastic.
- V -
A fixture installed behind a horizontal shielding over a window or along
a wall. Light is distributed up and down, usually from a fluorescent source.
Fixture used at a mirror or over a vanity bathroom mirror. Ideally a long,
well diffused light source.
On a ceiling fan, rubber wheel that holds blade holders.
Thin sheet of material, usually of wood or plastic that is attached, laminated,
to a stronger, less costly material.
A style derived from the late 19th century British period. Typical of
Victorian lighting details are candelabras with decorative ornaments,
colored glass lanterns, fixtures with brass and cut glass, and dangling
Unit of electricl force or pressure. Household voltage in the United States,
nominally 120 volts, varies between 110 and 125 volts.
Difference in voltage along a circuit. Voltage drop becomes a problem
with low voltage wiring and small cable, reducing the intensity of the
lights at the far end of the cable.
- W -
Fixture designed to be mounted on a vertical surface, including sconces,
urns and valances.
A broad term which refers to fixtures that provide general, task and accent
lighting. Many wall-mount fixtures are designed to match and coordinate
with dining room chandeliers or other lighting fixtures. Wall brackets
are often used for task lighting at the bathroom mirror. They are available
in a choice of incandescent, halogen and energy efficient compact fluorescent
A lighting technique in which light is aimed down a wall for a grazing
effect. For dramatic shadows, especially on textured surfaces such as
brick, draperies or stone, mount the lights 6 to 12 inches from the wall,
with the fixtures the same distance apart and aimed downward.
Lighting directed on a wall or vertical surface to emphasize that plane,
enhance the surface texture, or bounce light back into the room. Increasing
wall brightness generally makes a room seem more spacious.
A lighting technique in which a wall is evenly washed with light. For
most surfaces, mount the track 2 to 3 feet from the wall on ceiling up
to 9 feet high. Mount between 3 and 4 feet on ceilings between 9 and 11
feet high. Space the fixtures the same distance apart for even light distribution.
A unit of electrical power.
The amount of electricity consumed by a bulb.
Distressed finish that simulates aging.
Also called a solderless connector. Small plastic device that can be fastened
over the bare, joined ends of several wires to protect and insulate the
Soft iron that is hammered and bent into decorative shapes.
- X, Y, and Z -
A heavy, colorless, and relatively inert gaseous element that occurs in
air as about one part in 20 million by volume and is used especially in
thyratrons and specialized flashtubes.
Outdoor lighting fixtures, including hanging pendant lamps, wall lights,
security lights and landscape lighting used to beautify and enhance an
In dimming, lights that are operated together. Also called Channel Lighting.
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