While I’m a big fan of LED lighting, the quality of LEDs largely depends on multiple factors!
A joint study by Pennsylvania State University and Soraa found that test subjects widely preferred violet-based LEDs of CRI 97 over typical blue-based LED with CRI of 85. Test subjects were asked their preference when viewing color and white objects under the two different light sources. The results were published on the Lighting Research & Technology academic website.
Using 48 participants in a carefully controlled psychophysical experiment, the study compared the perception of colored objects, a white shirt, human skin, and teeth under the two sources. The participants largely preferred the violet-based LEDs over the blue in both the colored and white objects.
Without question, developments that go beyond the CRI metric, like whiteness, can influence consumer preference. This realization has pushed LED vendors like Philips Lumileds, Luminus Devices, and Soraa to test new LED formulations for better white rendering.
The research also demonstrates that light quality should be considered as important as efficacy in light sources. For many consumers and retailers, they do not want to sacrifice excellent light quality for economic and environmental benefits.
Who wants to save on the energy bill if the light quality is poor and unattractive?
As pointed out by Illumination Engineering Society (IES), the commonly used Color Rendering Index (CRI) metric is not entirely adequate to measure the light quality of LEDs. And while we wait for an improved color fidelity metric, a metric on whiteness rendering does not even exist! Fortunately, IES is beginning to look at whiteness and improve the understanding and metrics for both white and color.
