Glossary of Lighting Terms

Accent Lighting
Light that aims at something. For example recessed lights that graze a wall or picture lighting.

Ambient Lighting
General overall lighting. Basic background lighting.

Something that shields a light or directs it.

Beam Spread
The width of the light aiming out of a bulb.

The difference between the color of something and the background.

The glass that shields the light bulb and spreads the light.

Putting lighting close to a wall aimed to bring out the texture in the wall.

A type of incandescent light bulb that is filled with halogen gas. They are smaller and brighter than regular light bulbs. The light is “white”, so things look the color they really are. It’s a good choice for putting makeup on by.

A regular light bulb. Light is produced when a tungsten filament is heated by an electric current until it is hot enough to glow.

1) What a lighting person will call a light bulb.
2) A lamp with a cord and a plug which they will call ” Portable lighting.”

A piece of glass used to protect a light bulb from dust or to redirect light.

A measure of a lamps light output.


A dull, not shiny surface. It doesn’t reflect as much light.

Recessed Lights
Lights that are set up into the ceiling. They consist of a can which usually has all the electrical parts and the socket and a separate trim, which is the part you actually see.

Task Lighting
Lighting that aims at a certain area so that you can do something, like put on your makeup or read in the tub.

UL Listed (UL Compliant)
Underwriters Laboratories, now just UL, is an American company that tests lighting to be sure it is safe. They’ve been around since 1894.

“UL helps companies demonstrate safety, confirm compliance, enhance sustainability, manage transparency, deliver quality and performance, strengthen security, protect brand reputation, build workplace excellence, and advance societal wellbeing. Some of the services offered by UL include: inspection, advisory services, education and training, testing, auditing and analytics, certification software solutions, and marketing claim verification.”

Underwriters Laboratories, tests products for public safety compliance. UL Listed means the product has been assessed and certified by Underwriters Laboratories. For more than one hundred years, Underwriters Laboratories has tested and certified Lighting products and accessories for their sale in many of the world markets. The UL Mark is widely recognized by consumers, retailers and authorities who trust UL’s integrity and commitment to consumer safety. Underwriters Laboratory tests every product to the highest standards to insure that any item that carries the UL Mark can be used by the consumer with confidence.

ULC or CUL Listed
“ULC Standards develops and publishes standards and specifications for products having a bearing on fire, life safety and security, crime prevention, energy efficiency, environmental safety, security of assets and facilities, live working and workplace safety and other areas. ULC Standards is accredited by the Standards Council of Canada as a consensus based Standards Development Organization under the National Standards System of Canada.”

UL Listed Dry Location
“A dry-location light must be installed in a location that is not normally subject to dampness but may be subjected to temporary dampness. Ventilation is often used to prevent an accumulation of moisture at the light, but the proper amount of ventilation is critical in extracting the moisture from the area. A very common application of this concept would be a dry-location light installed above a mirror or vanity in a bathroom. A light installed in a shower, where it is in close proximity to steam and water splash must be a damp- or wet-location light and marked ‘Suitable for Damp Locations’ or ‘Suitable for Wet Locations.'”

UL Listed Damp Location
“A damp location is a location, either exterior or interior, that is normally or periodically subject to condensation of moisture in, on or adjacent to the light. Article 100 states these are locations often protected from weather and not subject to saturation with water or other liquids but may be subject to moderate degrees of moisture. These could include partially protected locations under canopies, marquees, roofed open porches and some basements, barns and cold-storage facilities, such as walk-in coolers, freezers and warehouses.”

UL Listed Wet Location
“A wet location is one where the light is subject to saturation with water or other liquids, such as in a vehicle washing area, or where the light is mounted in an unprotected location and directly subjected to the weather. Underground installations and installations where concrete slabs or masonry are in direct contact with the earth are also considered to be wet locations…. A wet-location light is one that is listed and marked as suitable for use in a wet location. These lights are tested to withstand water and other liquids that may drip, splash or flow on or against the light. However, a light marked as ‘Covered Ceiling Mount Only’ is intended for wet locations where the light is not subjected to water and precipitation from the back of the light, such as in a vehicle washing area. Conversely, a wet location ceiling light that does not have this marking can be mounted where it is subjected to moisture from the back, such as on a metal-grate catwalk. Lights marked ‘Suitable For Wet Locations’ are intended to be installed at least 4 feet above the ground since the light has not been tested for water intrusion from the ground, such as from a lawn or garden sprinkler system. A wall-mounted or post-mounted light may be installed within 4 feet from ground level where the light is marked ‘Suitable For Mounting Within 4 Feet of Ground.’ This same rule holds true for a light with an integral post (such as a bollard-type light) and must also have this same marking.”

The unit of measure of electrical power. It does not measure light output. That is measured in lumens. An efficient light fixture will give you more lumens, light using less power, watts. For example the Holtkotter (Holtkoetter) Viennese Low-Voltage Pendant 5590/4 is lit with 65-Watt Halostar IRC bulbs by Osram. This is equivalent to one 125 Watt incandescent bulb, approximately 7000 Lumens. So it gives the same amount of light for half as much electricity.

“Save up to 65% lighting costs! New OSRAM economical halogen lamps. IRC lamps are up to 65% more economical than standard halogen lamps, as a result of a special coating on the lamp bulb (IRC = Infra Red Coating). The convenient ENERGY SAVER calculator allows you to easily calculate your individual cost saving.
The outstanding feature of the innovative ENERGY SAVER lamps is their increased luminous efficiency – i.e. the same amount of light is produced using less power, therefore saving energy. They also cut down on air conditioning costs, because the lower power consumption (for the same amount of light produced) generates less heat, and therefore reduces the cooling requirement.
That means cash in your pocket – without having to do without brilliant light. All IRC lamps provide an extremely high level of light intensity and colour constancy over their entire life of up to 5, 000 hours!”

If you want more light for your money, Fluorescent is always an excellent choice.

“Philips T5 Fluorescent Lamps are incredibly powerful, environmentally-responsible, long life lamps with an ultra-slim profile.This translates into reduced maintenance and disposal costs and also allows the use of smaller fixtures—which reduces ceiling clutter. For the longest life in this lamp family, Philips SILHOUETTE™ Long Life T5 High Output lamps have a rated average life of 35, 000 hours based on 12 hours per start!
Philips T8 Fluorescent Lamps provide long life and high performance, which translates into reduced maintenance and disposal costs. ALTO® lamps are low mercury and TCLP-compliant . This makes them a sustainable lighting solution, since less mercury combined with energy efficiency, reduces the impact on the environment. Hi-Vision® Phosphor combined with Philips’ exclusive cathode guard delivers 95% lumen maintenance and reduced lamp-end blackening. Philips T12 Fluorescent Lamps provide highperformance and long life in a wide range of sizes, shapes, and types. The Advantage T12 Series of lamps provide ultimate performance with long life (24, 000 hour rated average life), 85 CRI, and the highest lumen output (3600 initial lumens) of any 40-watt four-foot T12 lamp available.”

“Our compact Fluorescent (CFL) bulbs bring all the advantages of Fluorescent lighting to regular incandescent sockets. They use up to 75% less energy and last up to 10 times longer. With a variety of wattages, shapes and sizes, these bulbs are the perfect for hard-to-reach areas.”

CFL Bulb Standard Bulb
15w = 60w
20w = 75w
26w–29w = 100w
38w–42w = 150w
55w = 250w–300w

This is by no means all the information there is.

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