Editorial: Lighting research in China

This special issue on Lighting Research in China was initiated to raise awareness of the work of researchers from China, for whom publication in an English language journal can present a particular challenge. The seven papers included in this issue cover a wide range of topics, reflecting some of the latest research carried out by Chinese researchers. The first two papers concern interior lighting. He and Yan carried out a field study in a luminaire factory in which the light level and correlated colour temperature were varied. They found that in comparison to the baseline condition (i.e., a dark condition), the light exposure can benefit workers’ subjective alertness and sleep efficiency, especially under the condition with a higher light level or a lower Correlated Colour Temperature. In the second paper, Hou et al. investigated the characterization of colour discrimination of light sources through a psychophysical experiment using the Farnsworth-Munsell 100 Hue Test and proposed two colour discrimination scores. In comparison to other metrics, the proposed scores are based on both the colour fidelity and colour gamut characteristics of the light source. The next two papers are investigations associated with road lighting. Qin et al. investigated how driving speed affected the driver’s pupil area and fixation zones when approaching the tunnel entrance under a normal lighting condition and found the fixation area and average pupil area have a negative correlation with the driving speed. Li et al. investigated the effect of pavement reflection on road lighting performance, in terms of luminance, uniformity and threshold increment through lighting simulation, providing guidance for design process. Photometric and colorimetric characteristics are important topics in metrology. With the development of imaging technologies, the characterizations are increasingly performed using cameras and sensors, which do not have perfectly uniform responses. The two papers from Xie et al. propose methods for modelling and correcting such non-uniform responses, improving the measurement accuracy. Last but not the least, though chromatic properties of effective light are important in lighting design and rendering, they are not easy to predict, measure and visualize due to the interactions between materials and lighting. The final paper in this issue, by Yu et al., reports the investigations on the effects of inter-reflections on the structure of the physical light field for diffusely scattering scenes and shows the importance to include six-dimensional light field effects of light–material interactions in spatial designs. These seven papers are just a small sample of work carried out by Chinese lighting researchers. We look forward to further important contributions in the coming years.