A New Way to Understand the Color Rendition Performance of Multi-Primary LED Lighting Systems: Color Rendition Variability (CRV)

Tunable, multi-primary LED systems offer the potential for easily customizable lighting solutions, particularly for color quality and other spectrally derived performance characteristics. However, testing and comparing the performance of these systems is substantially more complicated than for fixed-output lighting products. This article reports on the development of a measure for characterizing the range of variation in color rendition that is possible for a tunable, multi-primary LED system – a characteristic deemed color rendition variability (CRV). The proposed CRV metric is derived from the set of metameric SPDs that can be created for a given product (real or theoretical) based on the measurements of individual LED primaries. It is a tool that provides composite information about the flexibility of the system that goes beyond minimum and maximum values for individual measures of color rendition, such as ANSI/IES TM-30 Rf, Rg, and Rcs,h1. The utility and face validity of CRV were evaluated using combinations that could be produced for 132 unique, theoretical multi-primary LED systems. The theoretical systems had four, five, six or seven LED primaries, each chosen from a set of 32 options. Thirty-three combinations of each size were established; three targeted selections mimicking typical combinations of LED primaries, and 30 random combinations. The results demonstrate how CRV can provide value as one of the many characteristics that might be optimized when developing a tunable lighting system.

可调谐多基色发光二极管（Light Emitting Diode，LED）系统可为实现高度定制化的照明解决方案提供可能，尤其在显色质量及其他光谱衍生性能指标方面。然而，相较于固定输出型照明产品，此类系统的性能测试与对比工作要复杂得多。本文提出了一种用于表征可调谐多基色LED系统可实现的显色范围变化的评测方法——该特性被定义为显色变异度（Color Rendition Variability，CRV）。所提出的CRV指标源自针对特定产品（实物或理论模型），基于各LED基色测量结果可生成的同色异谱光谱功率分布（Spectral Power Distribution，SPD）集合。该指标可提供关于系统灵活性的综合信息，其涵盖范围远超诸如ANSI/IES TM-30标准下Rf、Rg及Rcs,h1等单一显色性能指标的最值范围。本文基于132种独特的理论多基色LED系统可生成的组合，对CRV的实用性与表面效度进行了评估。这些理论系统分别搭载4、5、6或7个LED基色，每个基色均从32种可选方案中选取。针对每种基色数量均设置了33种组合：其中3种为模拟典型LED基色组合的定向选取方案，剩余30种为随机组合方案。研究结果表明，在开发可调谐照明系统时，CRV可作为诸多需优化的特性之一发挥其应用价值。