Color MIXING LIGHT Misconceptions and problems Mixing light

Color MIXING LIGHT

Misconceptions and problems � Mixing light can get very confusing to many students because most have never done it. � We have mixed pigments and try to apply that to mixing light. � Light is the reverse of mixing pigments so it causes some disbelief. � Trust your eyes and not past beliefs.

Color by addition � Unlike pigments each time you add a color of light you are just adding more to the mix, not subtracting. � If you add all colors you should get white. � To make black you remove all light (turn them off). � Look at a T. V. or computer screen. � When � They they are off they are black. can make white (and every other color) by adding different colors of light to the screen.

Additive Primary Colors � The additive primary colors are red, blue and green. � You will notice these are three color controls on TV’s and a computer screen � Complimentary colors (made by mixing two primary colors) are magenta, cyan and yellow.

Mixing the additive primary colors in equal concentrations Red Magenta Blue White Cyan Yellow Green *Almost identical to the pigment triangle, just rotated.

Pure and mixtures The primary colors are considered pure, the complimentary colors are mixtures. True primary red is only Redred light Magenta Blue White Cyan Yellow yellow is a mix of green and red. Green

Why things look different in different sources of light. � The most obvious is under a “dingy” light (yellowish) � This happens when a gas light gets old, it doesn’t put out the high end of the spectrum (blue) like it should so the light is yellow. � These are found in several parking lots. � Even though the pigment on your car, shirt or skin may reflect blue; if there is no (or little) blue present, it can’t be reflected.

So that means… � Things will look odd under that light (all blue has been subtracted out). � To a lesser extent this happens with the differences between incandescent, fluorescent, and sunlight.