Perception is Reality: Visibility in Architectural Lighting Research

How architects measure light is changing. Human perception of light is ostensibly the reason why spaces are illuminated, yet primary lighting guidelines used by architects measure how much light is falling on a surface, not the distribution of light to the human eye (Cuttle 2011). Recent lighting research related to human visual perception introduces new ideas that, while they challenge the status quo of lighting practice, build on decades of respected prior research. In this paper’s case in point, researchers are developing new methodologies and tools to study luminance distribution in built environments (Inanici & Navvab 2006). The concept of studying luminance, or perceived light, instead of only illuminance has long been established in texts by leading lighting designers and researchers (Lam 1977, Boyce 2003, Steffy 2008). This paper aims to provide information on luminance distribution as a factor of emerging importance in the design of quality illuminated environments. To this end, it reviews the use of illuminance and luminance metrics in contemporary architectural lighting practice and research contexts, exposing the objective and subjective aspects of light that these terms measure. It finds that new tools that analyze luminance data from high dynamic range photography and digital simulation models are joined by new lighting knowledge dissemination platforms, together breaking down barriers that prevent architects from designing with luminance concepts. Examination of these research and knowledge tools reveals a shift to a cross-disciplinary, user-centered approach to architectural lighting where realities of human visual perception and surrounding physical contexts enjoy renewed attention.