Luminaire Manager- Description Tab

The Description tab displays the descriptive text read directly from the manufacturer'sIES photometric file and presents it in the lower portion of the tabbed area. The upper portion shows the results of metrics calculated by ElumTools: CIE Indoor Classification and Luminaire Efficacy Ratio (LER).




Indoor Classification - This is the "CIE Class," a classification of the luminaire's light distribution based on the amount of flux emitted in the upper and lower hemispheres relative to the total light emitted.


Classification % Uplight (above 90 degrees) % Downlight (below 90 degrees)
Direct 0 - 10% 90 - 100%
Semi-direct 10 - 40% 60 - 90%
General-diffuse 40 - 60% 40 - 60%
Semi-indirect 60 - 90% 10 - 40%
Indirect 90 - 100% 0 - 10%



Luminaire Efficacy Rating (LER) - LER is a measure of a luminaire's energy efficiency. LER is equal to the luminaire's lumen output divided by its input power. LER has only been validated for the following indoor distribution luminaires described by the National Electrical Manufacturers Association (NEMA): fluorescent, commercial downlights and HID industrial luminaires. The luminaire product category is not reported by ElumTools, only the LER value, as the product information is not extractable from the IES file.




EFF = Luminaire efficiency

TL = Total lamp lumens (Note #2)

BF = Ballast factor

W = Luminaire input watts


LER Notes:

  1. LER can not be calculated if watts=0 or ballast factor = 0
  2. When calculating LER for absolute photometry (lamp lumens = -1) , the calculated Luminaire Lumens value is used instead of Total lamp lumens x Luminaire efficiency.
  3. LER will not be calculated properly for IES files prorated to 1000 lumens (or other prorations) - it would be artificially low.


Descriptive Information


The text "Description" for a luminaire is typically created by the testing laboratory and often edited by the manufacturers marketing department to reflect accurate catalog numbers and/or product descriptions. It may range from extremely verbose to almost non-existent.


The format of this information is dictated by the IES document LM-63-02 (latest). This document is available from the publications store at .