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> Within certain ranges, of course.

Citation needed. I've never heard of human senses being anything else than logarithmic.



Sure, here you go. I said "within certain ranges" because there are absolute limits on either end. I hope it's obvious to you that the logarithmic approximation is only logarithmic until it isn't. The human visual response to staring at the midnight sky and staring at the noon sun are both non-logarithmic relative to the well lit everyday objects you usually look at. The valid range does not extend infinitely in either direction, and at the ends response ceases to be logarithmic even if the middle of the range works out well.

So, I think no citations are needed to explain basic absolute limits and the simple fact that logarithmic perception is only valid "within certain ranges." But, since you asked for citations, here are some starting points for understanding lightness perception, and how it's not quite logarithmic even in the middle of the valid range.

http://www.telescope-optics.net/eye_intensity_response.htm

"All this only scratches the surface of the complexities of eye response to light intensity, but should illustrate well that the common notion of it being described as simply logarithmic is oversimplification, to say the least."

https://en.wikipedia.org/wiki/Lightness

"At first glance, you might approximate the lightness function by a cube root, an approximation that is found in much of the technical literature. However, the linear segment near black is significant, and so the 116 and 16 coefficients. The best-fit pure power function has an exponent of about 0.42, far from 1/3."

https://en.wikipedia.org/wiki/Weber%E2%80%93Fechner_law#Visi...

"The eye senses brightness approximately logarithmically over a moderate range (but more like a power law over a wider range)"

https://en.wikipedia.org/wiki/Absolute_threshold

"For white light, the absolute sensitivity found was 5.9 x 10−14 watts / steradian-cm2"

https://en.wikipedia.org/wiki/Orders_of_magnitude_(luminance...

"100 Mcd/m2 Possible retinal damage[1]"

https://www.ecse.rpi.edu/~schubert/Light-Emitting-Diodes-dot...

see page 276, Fig. 16.2 "Approximate ranges of of vision regimes"

http://retina.anatomy.upenn.edu/~rob/lance/units_photometric...

See "Light levels important to vision"




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