A study of scene brightness perception was conducted to assess whether spectral sensitivity for scene brightness perception at low to moderate light levels (∼3-110 lux) could be partially explained by a contribution of intrinsically photosensitive retinal ganglion cells (ipRGC). An experiment was conducted at two different light level ranges and using two different spectral power distributions. The results suggest an increase in short-wavelength spectral sensitivity as a function of increasing light level. The results also confirm that including ipRGC as well as cone photoreceptor input in scene brightness spectral sensitivity resulted in improved predictions compared to including either cone input only or rod as well as cone input.