2024 Superb Owl on CTC-5

[Alex KL-1]

Originally Posted by old_tv_nut

The things you speculate about the psychophysics of color are true.
Highly saturated colors appear brighter than a gray of the same luminance.
Monochrome images require more contrast than color to give the same impression of discrimination between objects.
People with normal color discrimination do vary in their sensitivity to the primary light sources, both for apparent brightness and for the ratios of primaries needed to match an intermediate wavelength.

In addition, because of the gamma of the picture tube and corresponding gamma correction in the camera, the reproduced luminance of saturated colors viewed on a monochrome picture is reduced.
For example, a full amplitude 100% saturated red has Y signal = 0.3, but the monochrome image has luminance of 0.3 ^ (CRT gamma). CRT gamma may be around 2.6, so the monochrome image luminance for this color is only
R=G=B=0.3^2.6 = 0.043, so visual luminance = 0.043. But when you add the color signals, the CRT puts out R=100% (G and B = zero), which has the correct visual luminance of 0.3.

Interesting!

BTW, the B pure signal, having low ratio to Y, is basically crushed to black visually. Is very noticeable in video games.