Randy Burkett of Randy Burkett Lighting Design examines the development of the Illuminating Engineering Society’s (IES) TM-30 color fidelity metric (Rf) as a significant improvement over the much-maligned Color Rendering Index (CRI). Color fidelity in the CRI system is only a part of what is needed to adequately assess color rendering. And it can be misleading. "TM-30’s addition of a color gamut metric (Rg), however," writes Burkett, "delivers an accounting of a light source’s saturation. When used with the procedure’s color distortion icon—a saturation 'fingerprint' of sorts—an understanding of how a light source will reveal color is heightened." Read the full story at Architectural Lighting.