Bottle model of colour vision with brown colour as an example

1. Bottle model of colour vision with brown colour as an example 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

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

3. 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.

4. 255 255 255 One pixel element in the monitor consist of three different lamps with different colour (red, green and blue). Check it with the eyepiece! When we see white light, all three lamps are switched on.

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

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

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

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

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

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

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

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

13. pixel 100 25 0 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.