Brightness additivity for a grating target.
D003118:Color Perception; D005556:Form Perception; D006801:Humans; D008266:Macula Lutea / Q000502:physiology; D008722:Methods; D010783:Photometry; D010786:Photoreceptor Cells / Q000502:physiology; D011601:Psychophysics; D012160:Retina / Q000502:physiology; D014792:Visual Acuity; D014794:Visual Fields