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dvernet

And only $\approx$ 4% are S cones? Pretty crazy, what's the reason for having such an uneven distribution?

kayvonf

Here's an interesting question that's been bothering me... (and the interwebs didn't give me a good answer when making this lecture):

We always say the human eye is most sensitive to green light. In other words, its luminous efficiency curve is highest near wavelengths we perceive as green. I hear this fact used as a justification for why the Bayer Mosaic pattern in a modern digital camera has a higher density of green pixels that red or blue. However, as is clear from the photo on this slide, the opposite is true in the eye: the spatial density of green cones is far less than the spatial density of red cones.

kapalani

Isn't the red cones more of a misnomer? The large wavelength cones are also pretty much centered around the green wavelength region right?

kayvonf

@kapalani. Ah, duh! That's a very good point!

kayvonf

Jump back to slide 18 to review what we mean by a sensor's response. You may also want to take a minute to understand why the response of a sensor is a measure of the inner product of two functions: in this case, the sensor's response function, and the input signal.

whdawn

So does it mean that some people's color blindness is due to the proportion of S M L cones, so they have trouble seeing some kind of colors?

kayvonf

There are a number of different reasons for color-blindness, but in all cases the point is that two spectrum that are not metamers for most humans do become metamers for a color blind human. That might be because of missing one type of cone in the eye, etc.