BGA Greener Lighting Guide Glossary

BGA Greener Lighting Guide Glossary

All of the data in this guide is self-reported by manufacturers. The BGA cannot independently verify this data. That said, we feel this is valid information for comparison between manufacturers. Below is the list of metrics and their definitions.

Basic Information

Here’s where you’ll find the basics about the instrument.


Company which the given instrument and provides the data below

Model Name and Number

These identifiers should be used if interested in further review of the product

Category (ellipsoidal reflector spotlight, wash light, automated light, cyc light, strip or batten light, other)

This broadly defines what type of instrument the we’re examining.


Brief description of the instrument.

Comments on environmental attributes

A brief statement as to why this instrument is a greener alternative to typical theatrical instruments in the given category. Look for comments on energy used, embodied materials and recyclability.

What is the light source? (tungsten, discharge, LED…)

What kind of light source is used within the instrument. This will give you a sense of the performance you can expect from the instrument.

Performance Data

Here’s where you’ll find the basic performance data of the fixture. You’ll find all of this performance data is compared against a series of benchmark color temperatures. For more on Correlated Color Temperature head here.

Maximum Input Wattage

Maximum amount of electricity instrument will use.

total lumen output @ CCT

Lumen output is a measure of the raw amount of light the instrument creates. This is different from how much light it delivers to the given target.

illuminance with 6’ diameter field (must provide ambient air temperature during measurement)

Illuminance is a measure of how much light is delivered in a given space. This will give you a sense of the efficiency of the instrument.

efficacy (lumens per watt)

This metric gives you a sense for how much light an instrument generates per watt used.


The Color Quality scale is a qualitative measure of how well a light source displays reflects colors back to the human eye.


This describes the maximum shift in color from the beginning of a source’s rated life to the end. This will be expressed in degrees kelvin.

dimming score

flicker score

lumen maintenance

This is a measure of how many hours it takes to for lumens output to depreciate to a certain percentage of their initial output. This will read as LM-80 or LM-70. An example is 50,000 hours to LM-70 this means that after 50,000 hours of use the light will generate 70 percent of it’s initial rated lumen output.

color maintenance

This is a measurement of LED color shift over time. White light LEDs have a tendency to shift in color temperature over long periods of time. This is exacerbated in high-heat applications like theatrical lighting.

total harmonic distortion

This describes how much sound an instrument makes while in operation. This is most important when dealing with moving lights which often require fans.

modulation frequency @ 100%/50%

This describes the tone of sound an instrument makes as it dims. When an instrument relies on electronics to dim, often the pitch of harmonic distortion changes.

color gamut (CIE 1976 UCS)

This measure is particularly important for color mixing fixtures. It represents the peak color output across the color spectrum.

color efficiency

color ratio

power factor

Environmental Data

This data specifically refers to how the instrument will impact the environment

mercury content

A measure of how much mercury was used to produce the instrument.


The dimensions of the fixture give you a sense for how much raw material went into the product.


This is important both as a measure of raw material, but also when considering trucking a load bearing. The heavier the gear the more fuel it will take to move it and to hang it.

rated life

This is a measure in hours of the rated life of a given source. With tungsten halogen and HID sources this measure will be to the death of the lamp. With LED source this will expressed as LM-70 or LM-80.

quiescent load

This is the amount of electricity the instrument uses when it is energized but not casting light.

embodied energy

This metric describes how much energy went into creating the instrument in the first place.

end of life plan

This describes the proper disposal of a fixture which will no longer be used. It should include the recyclability of the product and how much work it would take to completely recycle the components that went into the instrument.

lithium content

Describes lithium quantity of instrument.

dimmer efficiency

Financial Data


Manufacturer suggested retail price.