The physiological and psychological bases for the Bayer color filter array

We interrupt the keyboard reviews for a post more closely related to photography. A poster on DPR made this statement: …color is a function of the wavelengths of light— which is why human eyes have three different varieties of ‘cone’ cells, each tuned for different wavelengths. Short-wavelength “S-cones” are tuned for ~450 nm, medium-wavelength “M-cones” ~540 nm, and Long-wavelength “L-cones” for ~570 nm. Bryce Bayer knew this and also understood the physiological reasons for having two greens but only one each of red and blue. This has nothing to do with psychology, it’s purely physics and physiology. This is wrong on many levels. However, unpacking the errors is interesting. What’s right is the names of the cone cells and their peak wavelengths. What’s wrong is thinking that the green and red layers in a camera’s color filter array (CFA) have much to do with the cone sensitivities, and complete omission of the impact of the human eye contrast sensitivity functions on the decision to…