Whole-Sky Luminance Distribution Maps from Calibrated Digital Photography

摘要

Sky luminance is an essential component in assessing the appearance and performance of internal spaces which are highly sensitive to the often dynamic luminance of the visible sector of the sky. Therefore, whole sky luminance distributions representative of real-sky sectoral dynamics over short time intervals are required. A modified scientific-grade digital camera was used to measure whole-sky luminance distributions of various sky conditions. Results showed acceptable correlation between the measured and calculated results for overcast and clear skies demonstrating the viability of using hemispherical digital photography for mapping whole-sky luminance distributions. However, intermediate skies showed distinct sectoral variations and dynamics supporting the argument for more accurate and respresentative luminance distribution data.