
Figure 21.7 CIE [x, y]
chart features
In Figure 21.7 in the margin, I sketch several features of
the [x, y] diagram. The important features lie on, or
below and to the left, of the liney= 1 -x.
When a narrowband (monochromatic) SPD comprising
power at
just
one wavelength is swept across the range
400 nm to 700 nm, it traces the inverted-U-shaped
spectral locus
in Ix, y] coordinates.
The sensation of purple cannot be produced by a single
wavelength; it requires a mixture of shortwave and
Iongwave light. The
line of purples
on a chromaticity
diagram joins
the chromaticity of extreme blue ...