Abstract
Presenter: Dr. Sam M Berman Senior Scientist Emeritus, Lawrence Berkeley National Laboratory.
Host: Dr. Christopher Tyler, Ph.D., D.Sc.
Abstract:
Melanopsin signals have been associated with light driven circadian entrainment, pupil size changes, and clinical assessments for conditions such as SAD and photophobia. However, these signals have a much broader influence on vision in that they can affect any visual assessment based on light level and where spatial brightness perception, rather than object brightness, is a component. This is because the calibration of light meters fails to account for contributions from the melanopic photoreceptors that are situated outside the retinal fovea, and that contribute to spatial brightness perception. The effects are demonstrated in a semi-realistic environment simulating a sports field that is lit with a series of large visual field metamers constructed to utilize the metamer method of Cohen & Kappauf. The study determines the quantitative augmentation required to assure that light meters provide a veridical assessment of light quantity consistent with perceptions of brightness.