New trends in physics teaching, v.4; The ... - unesdoc - Unesco

New Trends in Physics Teaching IV
white, or neutral, point would give the same sensation as 497 nm or its complement in the one
case, and 493 nm in the other. Anomalous trichromatism occurs in about 7 per cent of the male
population. Some are said to be red weak - red appears very dim in most situations - others are
green weak.
APPLICATIONS OF THE CIE DIAGRAM
A colour television screen is covered with a microscopic array of phosphor dots emitting red, blue
and green light. The Federal Communications Commission specified the three points B, G and R
on the diagram of figure 14 as the broadcast standard for the chromaticity co-ordinates.
.9
.8
.7
.6
Y
.5
.4
.3
.2
.I
.I .2 .3 .4 .5 .6 .7
X
Figure 14. Chromaticity diagram showing the Munsell printed colours of maximum saturation (polygonal figure), the primary
colours specified by the United States Federal Communications Commission for broadcast (RBG) and the negative primary
colours used by KODAK in a co1o::r film (CYM).
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