Last Thursday Donald Trump spoke to a group of Republicans in Baltimore. One of the things he said caught my attention: “The lightbulb. People said what’s with the lightbulb? I said, here’s the story. And I looked at it, the bulb that we’re being forced to use, No. 1, to me, most importantly, the light’s no good. I always look orange. And so do you. The light is the worst.”
In 2007 Congress passed the Energy Independence and Security Act(EISA) with the goal of increasing energy efficiency across the economy. Part of EISA has affected the lighting industry in the form of mandated efficacy of light sources. The initial efficacy rules targeted A-Lamps (standard household light bulbs) and set the efficacy level above that of incandescent but below that of halogen lamps. The result was a slow shift to the more energy efficient technology. Over the years the energy efficiency requirements have been expanded to more lamp shapes, always in keeping with technological ability so that we never faced a lamp shortage or loss of a lamp shape. Today, more than 50% of lamps sold are LED that exceed even the most stringent requirements.
Science geeks everywhere are celebrating World Metrology Day today. Today has also been chosen by Bureau International des Poids et Mesures (International Bureau of Weights and Measures) to implement changes to the International System of Units or the SI. The changes are to the definitions of the kilogram, ampere, kelvin, and mole.
Last Friday I took my class on a visit to a fixture manufacturer’s showroom. The visit was pretty successful, but I had one issue with the information that was presented. This manufacturer’s rep presented their CRI 80 and CRI 90 products by saying that CRI 80 dulls colors and CRI 90 makes colors “pop”. I can’t blame him too much, after all it’s a common misconception that higher CRI is “better.” However, it’s not true so let’s take a look.
A couple of weeks ago the Global Lighting Association (GLA) published Application of CIE 13.3-1995 with Associated CRI-based Color Rendition Properties. It proposes TM-30 like metrics to supplement CRI Ra. Specifically, it proposes a color gamut index, Ga, that is similar to TM-30’s Rg and a set of chroma indices, Ci, similar to TM-30’s Rch,hj. At first glance I can see some specifiers getting excited about this. Since it’s based on CRI it’s already somewhat familiar so it should be easier to learn. But…