LED-based light sources optimised for high colour rendition from an end users' perspective

Light emitting diode (LED) technology is continuously developing, leading to the current transition from simple phosphor-converted LED lamps to LED lamps optimised for high colour rendition in residential lighting. To assess whether such optimised phosphor-converted LED lamps may fulfil the end users' needs better than simple phosphor-converted LED lamps we asked participants to rank two particular brands of phosphor-converted LED lamps optimised for high colour rendition, a typical simple phosphor-converted LED lamp and a halogen lamp for pleasantness, naturalness and purchase preference. The results of two experiments suggest that phosphor-converted LED lamps optimised for high colour rendition have the potential to outperform simple phosphor-converted LED lamps and even to measure up to traditional halogen lighting in terms of user preference. However, this is not the case for all phosphor-converted LED lamps optimised for high colour rendition. From the end users' perspective, unfortunately, it is currently difficult if not impossible to choose the LED light source that one would prefer most. Practitioner Summary: Considering innovations in LED technology, we assessed the potential of LED lamps optimised for high colour rendition to outperform their predecessors regarding user preference. In one of two conditions, these optimised LED lamps outperformed a simple phosphor-converted LED lamp and measured up to halogen lighting. Abbreviations: LED: light emitting diode; CCT: correlated colour temperature; CRI: colour rendering index; CIE: Commission Internationale de l'Éclairage; CRI Ra: CIE General Colour Rendering Index; K: kelvin; lx: lux; GFC: goodness of fit coefficient; BLED80: simple blue-pumped phosphor-converted LED with a CRI Ra of 80; BLED96: blue-pumped phosphor-converted LED optimised for high colour rendition with a CRI Ra of 96; VLED97: violet-pumped phosphor-converted LED optimised for high colour rendition with a CRI Ra of 97; R9: CIE Special Colour Rendering Index for red; ANSI: American National Standards Institute; IES: Illuminating Engineering Society; Rf: IES Fidelity Index; Rg: IES Gamut Index; CC: chromaticity coordinates.