Intensity and ratios of light affecting perception of space, co-presence and surrounding context, a lab experiment

In this paper, we investigate how intensity of light in a space and ratios between light a space and in its surroundings affect perception of the atmosphere of the space, experience of co-presence and perception of the surrounding context. A preliminary field study in urban public transportation waiting areas showed, through observations and interviews, that the intensity of light influenced how participants experienced the waiting area and its urban surroundings. In this lab experiment, we investigate the perceived qualities of light levels in a controlled environment and thereby inform future field tests of light intensity and ratios in complex urban contexts. The lab setting consisted of two light zones that simulated 1) a public transportation waiting area and 2) the surrounding urban context. We surveyed thirty participants on their perceptions of six lighting scenarios with different light intensities and ratios and asked them to respond to questionnaires based on a semantic differential scale. Non-parametric data from the questionnaires were statistically analyzed. Luminance data were documented in high dynamic range (HDR) photos and luminance maps to document the light perceived by the human eye. Results revealed that participants perceived the atmosphere in the simulated waiting area as relaxed and private when luminance intensity was low. Furthermore, they perceived the lighting as harmonious and less glaring when luminance ratios between the waiting area and the surroundings were low. However, results also showed that higher intensity lighting in the surroundings increased object visibility but did not indicate that contrast influenced visibility.