Measurement and interpretation of luminous ambience

This paper presents part of a multidisciplinary work with three teams: two laboratories of psychology and a laboratory of lighting/architecture. We concentrate here, within the project, on activities on luminous ambience and focus on the lighting/architecture part. The problem we studied was:

  • How is it possible to concisely express the variety of luminous ambience qualities on the basis of a large number of light measurements? More precisely, in order to analyse the quantitative data collected from measurements, we intend to define interpretation models. The result of these interpretation models should be easily usable for further analysis and understandable by architects. Architects do not manipulate expressions such as luminance levels. In order to express their intentions for a luminous ambience, they use qualitative and descriptive expressions.
  • On the basis on these interpretations, how can we change the existing concept of artificial lighting for a space in order to lessen energy costs, to keep a good performance of lighting and to improve the comfort and pleasantness of users? More precisely, comfort and pleasantness are closely linked to contrasts thresholds, gradual ranges of luminance and chromaticities on the interior envelope. Artificial lighting is used by the general public and designers not only to reach a sufficient level of lighting on work surfaces, but also to increase or decrease contrasts and gradual ranges of luminance and modify the colour of the light on the interior envelope in order to reach a comfortable and pleasant ambience. In that respect, we can say that the expenditure in electric energy is also due to the fraction of artificial lighting used to create comfort and pleasantness of ambience.

To address these two questions, we have studied existing luminous ambience in two sites in Paris. The spaces under study were rest areas. We defined the method for light measurement on the opaque and glazed interior envelope (with luminancechroma and luxchroma meters) in mixed lighting (both natural and artificial). We interpret the measurements in terms adapted to architects. We defined the concepts for different luminous ambiences and built these modified ambiences in the sites themselves.

Measurement and interpretation of luminous ambience