The National Lighting Bureau recently presented a panel on color metrics at its Annual Lighting Forum, focusing on the proposed IES method TM-30 and available for viewing online.
Moderated by EdisonReport Editor and Publisher Randy Reid, the panel included IES Industry Relations Manager Mark S. Lien, LC, CLEP, CLMC, HBDP, LEED BD&C; Greg Yeutter, with lighting-manufacturer LUXTECH; and Randy Burkett, FIALD, FIES, president of Randy Burkett Lighting Design, Inc.
The method being proposed in TM-30 uses two metrics to describe a light source’s color rendering properties: fidelity, which resembles CRI in many respects, and saturation, considered through an all-new metric called gamut that indicates how saturated an illuminated color appears to be. Research suggests gamut may be as important or more important than color fidelity.
Lien cautioned TM-30 is not a final document: “It will be changed,” he said, noting that optimal finalization will result in an American national standard, via the IES, and, hopefully, an international standard, via the Commission Internationale de l’Eclairage (the International Commission on Illumination, or CIE). He warned that, because near-term change is inevitable, fully adopting the working metrics in TM-30 would be premature. He commented that the IES developed and issued TM-30 solely as an initial test process for lighting experts to evaluate and improve. Right now, the most daunting challenge associated with TM-30 is not so much finalizing the fidelity and gamut metrics as it is helping people understand them and how they interrelate.