PSYB51H3 Chapter 5: PSYB51-Chapter 5 Notes
Document Summary
Three steps to color perception: several problems must be solved in order to go from physical wavelengths to the perception of color. Moreover, we want those perceived colour to go with the object (blood is red) and not to change dramatically as the viewing condition change (blood should remain red in a sun and shadow, for example) Step 1: colour detection: the cones that have a peak at about 420nm are known as short- wavelength cones (s-cones for short). The middle wave-length cones (m-cones) peak at about 535nm, and long wavelength cones (l-cones) peak at about 565nm: remember also that cones work at daylight (photopic) light levels. Step 2: colour discrimination: we know that diferent wavelengths of light give rise to diferent experiences of colour, and the varying responses of this photoreceptor to diferent wavelengths could provide a basis or colour vision. But there is a problem: suppose we change the wavelength to 450nm.
