Faq_terms

Lighting Terms And Definitions Lamp | Types of Lamps | Bulbs | Fixture | Color Rendering Color Temperature | Light Output | Light Spread

Lamp The correct term for the manufactured unit that produces light is a LAMP. We use this term as it common in our industry. Do not confuse it with FIXTURE. Common Types Of Lamps Incandescent Halogen Fluorescent CFL or Compact Fluorescent Lamp Metal Halide High Pressure Sodium Specialty

Bulb Many people use BULB in place of LAMP. However LAMP is still the correct term. We use "bulb shape" to identify the shape of the LAMP. For example the common Lamp you have on the end table next to your bed is an "A" bulb shape. The "PAR" is the shape of many directional halogen lamps.

Fixture The fitting that the lamp screws or plugs into that supplies power. The "fixture" in your kitchen may take a Fluorescent "Lamp". The fixture you have in your bedroom may take an "incandescent lamp". We sell Track Lighting Fixtures that use "halogen lamps"

Color Rendering (CRI) A measure of lighting quality. This measure is based on an index that ranges from 1 100 with natural daylight and halogen lighting being 100 CRI (color rendering index). Objects (such as artwork, jewelry, fabrics) illuminated with halogen lamps that have a high CRI, will appear more true to life. Color of objects can be perceived more accurately under lamps with a high CRI. Another wonderful side effect of high CRI light sources is that they produce a higher perceived level of light (they look brighter) which in turn makes them more energy effective (you save money). Color Rendering Of Common Lamps Incandescent 100% Halogen 100% Fluorescent 60% up to 92% Metal Halide 65% up to 92% High Pressure Sodium 21% up to 85%

Color Temperature Simply the measure of the COLOR of light. Not to be confused with color rendering, as they are

not associated with each other. An example of Color Temperature is the color difference of light between the white-hot light of high noon versus the warm color of light right before sunset. The Color Rendering never changes during the day (it stays at 100%). Color Temperature is measured in Kelvin Degrees. Halogen light is usually about 3000k however the new SoLux is manufactured at 35k, 41k, and 47k. The 47k works excellent on diamonds. The color of light can be measured by its color temperature. Color temperature is measured in units known as degrees Kelvin, named after Lord Kelvin, the developer of this measurement system. The following table shows the color temperatures of common light sources. Light Source Color Temperature Clear blue sky 12,000 Overcast sky 7,000 Sunlight 5,000 Metal Halide 4,500 Solux 3,500 to 4,700 Halogen 3,000 House Lamp 2,500 Candle Flame 1,500 When you view an object under light sources of different temperatures, its color will vary. If you print this page and are reading under natural, direct sunlight (5,000 degree), you'll see the bright white of the paper. On the other hand, if you are reading this page by candlelight (1,500 degrees), you'll see it as a warm yellow. This apparent color difference is due to the differing color temperatures of the light sources. It is important to view color-publishing work under daylight-balanced, 4700 to 5000 degree lighting to see accurate color. That's why a viewing booth is important. Many publishers use a desktop or portable viewing booth for their work, and then view the printed piece under a large viewing stand at the printer. Since the lighting is consistent between the two viewing environments, you can accurately judge the color. Make sure your light source has a 100% CRI to see the full spectrum of visible colors.

Light Output The amount of light output of directional lamps such as PAR lamps are measured in candlepower units. Candlepower is the intensity in any one direction from the standard candle is called one "candela" (formally called "candlepower") Most PAR and MR-16 lamps are measured this way. Lamps that have light coming out in all directions such as a common incandescent household lamp and the popular energy efficient screw in fluorescents are measured in Lumens. When considering the light output, compare it to the amount of energy consumed. Be careful when considering a light source to look at ALL aspects of its output. A lamp that has excellent output may have poor color rendering. Long life lamps may have great CRI but may be poor when considering energy consumption. Consider and compare the following when making an informed choice of lamp type: Cost Life Wattage Output (candela, candle power, or lumens) CRI

Color temperature

Light Spread The amount of coverage area you will get from a light source is determined by the spread of the light. Example " if you have a 12 degree spot pointed at an object 4' feet away you will get a 1' foot in diameter circle of light." As an example, a 40-Degree would be considered a " Flood" where as a 10-Degree would be considered a "Spot".