Objectives of this project are based on the domestic conditions of Taiwan to investigate and to analyze the phenomena of the impacts of light pollution on people's feelings of discomfort, and to propose the related tactics and recommendations. Through survey of the relevant regulations and the scientific literatures and the collection of pleader cases, this research focuses on both perception of glare and flicker via controlling the luminance of LED billboard, the luminance of background, the dose of duration and 9 kinds of video contents. The main tasks include (1) measurements of light pollution source and (2) study on the borderline between comfort and discomfort (BCD) of human perception and cognitions to perform subjective evaluation of glare and flicker at night condition. Finally, according to the domestic status and experiment results and the evaluation of influence of light pollution on people's life to investigate the feasibility of improvements related to light pollution.
This program has finished all milestones on schedule. First, this study made summary and translation above 6 literatures. Second, in the measurement and analysis of light pollution, this work conducted 132 measures for the selected LED billboard, analyzed the changes in the brightness of the light source and frequency domain analysis for 9 motion pictures, used dynamic imaging luminance measurement device to measure 9 testing videos at varied brightness of LED billboards. Third, the experiments have conducted for BCD of light pollution. The questionnaire included the overall glare, the maximum glare, local flicker, maximum flicker. There were 20 participants involved and 3240 data were recorded. The experimental results and conclusions are described as follows.
For the perceived maximum glare, four main effects of luminance of LED, luminance of background, video type and age were significant. The interaction of luminance of LED and dose was significant. The interaction of luminance of LED billboard and age was also significant. For the perceived maximum flicker, three main effects of luminance of LED, dose and video were significant. The interaction effect between video and luminance of LED was significant. There was also significant interaction effect between video and age. According to the glare perdition model, this study lists a luminance recommendation table of Glare for motion pictures.
According to the flicker perdition model, this study lists a frequency magnitude recommendation table of flicker for motion pictures. Based on the time-series analysis of occurrences of the maximum perceived glare and the maximum perceived flicker, this study discusses the feasibility of current measuring instruments and methods. Based on the results of subjective evaluations of light pollution, a new dynamic imaging luminance measurement device is adopted for measure glare, flicker and comfort rating as well. The results revealed that there were a reasonable correlation between the new device and subjective data.