Testing a provisional model of scene brightness with and without objects of different colours

A provisional model of brightness perception for illuminated outdoor scenes was recently proposed based upon a combination of photopic and short-wavelength cone spectral sensitivities, where short-wavelength cone sensitivity increases with radiance. An experiment was undertaken to determine whether coloured objects within the illuminated scenes affected overall scene brightness perception and, in so doing, to provide a test of the provisional model. The results suggest that overall scene brightness perceptions are, for the range of light sources and light levels selected, consistent with the provisional model and that scene brightness perception is independent of object colours within the illuminated scenes.