Inferring light characteristics in spaces with multiple light zones

Light zones are spatial groupings of lighting variables (intensity, direction, etc.) significant to the space- and form-giving characteristics of light (Madsen, 2007). Previously, Kartashova et al., (2015) found that for paintings in which more than one light zone was present the light inferences showed striking individual differences. We investigated this matter further to study if the light inferences are influenced by the orientation of the zones relatively to the picture plane. We created a scene with two light zones, contrasting mainly in light direction, in the a) left and right (condition LR) and b) front and back parts (condition FB) of a space. A grid of locations across the scene was tested using probes (white matte spheres). The observers’ task was to set the light on the probe (one per trial) as if it belonged to the scene. For condition LR the settings were highly consistent over observers and rather different in direction between the two zones. Contrarily, for condition FB we found high inter-observer settings variability, suggesting that observers estimated the relative sizes of the zones differently. We will further investigate the relation of these findings with space perception.

Funding: This work has been funded by the EU FP7 Marie Curie Initial Training Networks (ITN) project PRISM, Perceptual Representation of Illumination, Shape and Material (PITN-GA-2012- 316746).