Color rendering index (CRI) is one of those lighting subjects that gets people breaking bottles over each other’s heads, but the world’s largest lighting company has made clear where it stands, as Signify announced it has redesigned its Philips office luminaires to produce a CRI of 90, up from 80, in Europe.
CRI is one way of measuring a light source’s ability to show the true colors and skin tones of things and people it is illuminating. While some lighting scientists strongly believe in it as a metric, others do not. (Editor’s note: CRI is the most widely used metric to describe the ability of a light source to render color. There are newer and more effective metrics such as TM-30 evolving, although CRI remains the de facto standard for now.)
Signify clearly does. In announcing the move up the index, it noted that a CRI of 90, with its truer rendering of colors, fulfills health and wellbeing specifications of the WELL Building standard defined by the New York City-based International WELL Building Institute. In its rating, Signify includes a minimum rendering of 50 for a red measurement called “R9.” (Editor’s note: R9 is a score that represents how accurately a light source will reproduce strong red colors, and it is often looked to very specifically for high-end lighting in hospitality and retail applications, for example. And higher CRI and R9 values have sometimes been traded off for better luminous efficacy values to meet certain qualifications for market transformation and/or energy regulations.)
“With the step-up of Philips Office specification luminaires to CRI 90 with R9 of 50 or higher, we comply with the color quality parameter in the WELL Building standard,” said Signify’s Georgiana Nichifor, European product manager indoor general areas.
“For a healthy appearance of skin tones, it’s important to have sufficient spectral power in the upper part of the visible wavelength range,” added Signify’s Kees Teunissen, scientist, optics light and vision. “ A red rendering index, R9 of 50 or higher, is one way of achieving this.”
The higher CRI applies to Signify’s FlexBlend, SmartBalance, PowerBalance, TrueLevel, and TrueLine luminaires all under the Philips brand. Signify’s former corporate name was Philips Lighting and it has retained the Philips brand.
The company claims to be the first to offer a CRI of 90 with an R9 of 50 or higher.
It was not immediately clear whether Signify will apply the new CRI levels to other geographic markets.
MARK HALPER is a contributing editor for LEDs Magazine, and an energy, technology, and business journalist (firstname.lastname@example.org).