U.S. Department of Energy - Energy Efficiency and Renewable Energy

Building Technologies Office – Information Resources

CALiPER Report 20.1: Subjective Evaluation of Beam Quality, Shadow Quality, and Color Quality for LED PAR38 Lamps

This December 3, 2013 webinar explored the findings of CALiPER 20.1: Subjective Evaluation of Beam Quality, Shadow Quality, and Color Quality for LED PAR38 Lamps and discussed what attributes to look for to increase the chances of getting an LED PAR38 lamp that has favorable lighting quality. Following the publication of CALiPER Application Summary Report 20: LED PAR38 Lamps, DOE's CALiPER program initiated several special investigations to dive deeper into more complex issues on the same set of PAR38 lamps. The first such investigation focused on human-evaluated characteristics, including beam quality, shadow quality, and color quality. Twenty-six of the Report 20 PAR38 lamps were demonstrated for members of the local Illuminating Engineering Society chapter, whose opinions were obtained by a questionnaire. Many of the LED products compared favorably to halogen PAR38 benchmarks in all attributes considered, but others had certain attributes, such as color variation within the beam or stray light outside the beam, that were unacceptable to the observers.