Which CFF law states that a flickering light appears brighter than a steady light of the same average luminance?

The Brucke-Bartley Effect is the appropriate choice, as this phenomenon describes how a flickering light can appear brighter than a steady light with the same average luminance. This effect occurs due to the temporal processing of visual stimuli in the human visual system; the brain is more sensitive to changes in luminance over time. When presented with a flickering light, the perception of brightness can be enhanced compared to a constant light, primarily because the visual system aggregates the flickering signals differently than steady signals.

In contrast, the other laws mentioned are related but pertain to different aspects of visual perception. The Ferry-Porter Law relates to the critical flicker frequency, stating that the frequency at which light flickers appears to be more continuous rather than discrete as the luminance level increases. The Granit-Harper Law describes the relationship between the intensity of light and spatial resolution, focusing more on contrast sensitivity. The Broca-Sulzer Effect primarily addresses how brief flashes of light can appear brighter than longer illuminations, depending on their duration, but is not specifically tied to the flickering versus steady comparison.

Therefore, the Brucke-Bartley Effect is the key principle explaining the observed phenomenon, where flickering light's perceived brightness exceeds