Light vs. Ink

Colors created by glowing dots are not quite the same as those created by ink on the printer. Screens use the RGB system described above. Inks use the CMYK system using the colors C yan (a kind of blue), M agenta (a kind of red), Y ellow, and blac K. This is why what you see on your screen is not quite the same color when you print.

Physics Lesson:
Color from mixing pigments: Ink and paint make colors by the colors that they reflect. The other colors are absorbed, or subtracted, from the light hitting the object. The primary colors for inks and paints are traditionally said to be red, yellow, and blue. It is more accurate to say magenta, yellow, and cyan. These cannot be created by mixing other colors, but mixing them does produce all other colors.

Color from mixing lights: Lights show the colors that the light source sends out (emits). The colors from different light sources are added together to make the color that you see. A computer screen uses this process. The primary colors for lights are red, green, and blue-violet. Mixed together, they can produce all the other colors.

Color from optical mixing: The illusion of color can be created by tricking the eye. Artists of the Impressionist period created paintings using only dots of color. Newspaper photos are made of dots, also. The human eye blends the colors to "see" shapes and colors that were not actually drawn with lines, just suggested by the dots.

Here we see a photo of a water droplet acting as a magnifying glass on a CRT screen. Notice that three colors of dots create the overall pink color on the screen due to different strengths of each color and the brain working its magic. (Photo: Julie Radalj)

Fun site! - Learn more from the University of Colorado, using interactive Java applets. (Java applets take a while to load. You will be happier if you have a fast computer and a fast Internet connection.)

The Big Picture about how the eye sees

CRT screens

LCD screens

Дата добавления: 2014-12-23