Weber–Fechner Law

The Weber–Fechner law refers to two related laws in the field of psychophysics, which are known as Weber's law and Fechner's law. Both of these laws relate to human perception, specifically the relation between the actual change in a physical stimulus and the perceived change. This includes stimuli that is received by all senses: vision, hearing, taste, touch, and smell. For instance, when a person perceives a light stimulus on a sunny day they might rate the stimulus as less intense than they would at night despite the light being the same wattage power.