Which law computes the Just Noticeable Difference on a light adaptation curve?

Weber's Law is a principle that suggests the Just Noticeable Difference (JND) for a stimulus is proportional to the magnitude of the stimulus itself. In the context of light adaptation, this law determines how much a change in luminance must occur for a person to notice a difference in brightness. Essentially, it states that the perception of changes in intensity is a relative measure—the larger the initial stimulus (in this case, the brightness of light), the larger the change must be for a subject to notice the difference.

When considering light adaptation, as the intensity of light increases, the threshold for detecting changes in light also increases. Weber's Law is particularly relevant here because it highlights how our sensory perception adapts to changes based on the original stimulus level. The law proves crucial in understanding the adjustments our vision makes as ambient light levels vary.

Other options mentioned do not specifically relate to the JND in the same way. Rico's Law is less commonly referenced in the context of light perception. The DeVries-Rose Law, while dealing with brightness perception, introduces a more detailed context involving logarithmic scaling, which isn't directly about the JND. The Dowling-Rushton Law focuses on the relationship between photon capture and stimulation in photoreceptors