PSL300H1 Lecture Notes - Lecture 23: Chromatic Aberration, Color Constancy, Color Blindness
Document Summary
Light has a wavelength the distance from one wave peak to the next. The visible wavelength spectrum is from 400 nm for violet to 700 nm for red (a tiny part of the electromagnetic spectrum) The reason is because the power in sunlight peaks there. Earth"s atmosphere is most transparent to these wavelengths. Sea water, where eyes first evolved is most transparent <500 nm. People can see some extremely powerful infrared lights, and people who have their ocular lenses removed can see a little into the ultraviolet range. A yellow banana reflects yellow light more than other wavelengths, a green banana reflects green. Color vision infers these reflectances which carry information. Inference is hard because wavelengths reaching the eye depend on illumination (e. g. , in a greenish light, even a ripe banana reflects mainly green) Humans can infer (deducing) intrinsic reflectances meaning in greenish light, a ripe banana is still yellow this ability is called color constancy.
