Matej Erjavec Gimnazija Jesenice Slovenia MatejErjavecsp si Nataa

Matej Erjavec, Gimnazija Jesenice, Slovenia, Matej@Erjavec-sp. si Nataša Vaupotič, Dept. of Physics, University of Maribor, Slovenia, Natasa. Vaupotic@uni-mb. si Supplementary material to the paper with the same title published in European Journal of Physics. 27 611 -620

radiance normalized spectral sensitivities of the cones E. H. Land, Scientific American, 108 (1977) threshold responses of the cones vary by large factors data of Smith and Pokorny avalilable at http: //cvrl. ioo. ucl. ac. uk relative spectral sensitivities of the blue and the red cones with respect to the green cones

In the dark the cones are not excited. Each type of the cone is presented as a bottle. When white light is falling into our eyes, all types of cones are equally excited.

One pixel element in the monitor consist of three different lamps with different colour (red, green and blue). 255 255 Check it with the eyepiece! When we see white light, all three lamps are switched on.

Filling of the red, the green and the blue bottles when we see red: pixel 255 0 0

Filling of the red, the green and the blue bottles when we see dark red: pixel 180 0 0

Filling of the red, the green and the blue bottles when we see less saturated red (milky red): pixel 255 50 50

brown dye spectral reflection from different brown surfaces brown tree leaf - acer brown tree leaf - rhus red and green cones are excited

Filling of the red, the green and the blue bottles when we see yellow: pixel 255 0

yellow spectral light also “fills” the green and the red cones equally we see yellow

Filling of the red, the green and the blue bottles when we see orange: pixel 255 100 0

orange spectral light also “fills” the green and the red cones, red cones more than the green cones we see orange

Filling of the red, the green and the blue bottles when we see brown: Brown is an unsaturated colour with low brightness and dominant wavelength in the yellow/orange spectral region. pixel 100 25 0