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Current time:0:00Total duration:1:34

Video transcript

now let's return to the human eye for a moment remember the human eye is the sensor which light must pass through to be perceived so we need to understand the limit of the human visual system in the 1920s experiments were done to map the color space perceivable by humans from purple all the way around the rainbow to this red this defines all colors of a single wavelength these are known as spectral colors and inside this region we have all combinations of those pure colors scientists plotted the limit of the pure colors we can perceive notice it takes this funny-looking shape one reason this shape is useful is something called perceptual uniformity that's a fancy way of saying that we can find the mixture of two colors such as this red and the screen by simply looking at the midpoint of them right here it's known as the CIE chromaticity diagram CIE refers to the scientific group that published the findings compare this to the hue saturation color wheel which is not perceptually uniform pure red is here pure green is here but the middle of these two points is not pure yellow at all it's a very desaturated yellow okay let's pause here in this next exercise we'll challenge you to think more about this CIE chromaticity diagram and perceptual uniformity