Color Rendering Index (CRI)

CRI (Ra) quantifies how faithfully a light source renders object colors compared with a reference source, on a scale where 100 is perfect. Industrial LED fixtures typically specify CRI ≥ 80, which renders safety markings, cable colors, and product labels reliably; CRI ≥ 90 is reserved for inspection, printing, and retail-grade tasks. Legacy HPS street lamps sit near CRI 20–25 — one reason LED conversion transforms perceived visibility even at equal lux. Ra is an average over eight pastel samples; saturated red rendering is tracked separately as R9, worth checking for camera-monitored areas and food or medical settings.