Day 11 52411 Topic Vision and Color Objective

Day 11 5/24/11 Topic: Vision and Color Objective: I will describe how colors are mixed for light and pigment. Science Starter: List the colors of a rainbow & answer the following: 1. Why is white not one of the colors? 2. Why are they in certain order? 3. Why isn’t pink one of the colors? Text Book Turn in, 20 min into class. < 10 min of class time.

Color and Light When all the colors of the rainbow are combined, we do not see any one color. We see light without any color. We call this combination of all the colors white light The colors that make up white light are called visible light. There are other forms of light that we cannot see, such as infrared and ultraviolet light.

Color and Light comes in tiny bundles called photons, each of which has its own color. The lowest energy photons are a dull red and the highest energy are a deep purple. Low Energy High Energy

Light is a Wave Light is also a wave. The frequency of the wave is proportional to its energy. Red has the lowest frequency and violet has the highest frequency.

The Subtractive Primary Colors • Colored items & paint pigment work by a subtractive process • Certain colors are absorbed/subtracted. • The colors we see are reflected. Sketch using color

The Additive Primary Colors We perceive different colors as a combination of percentages of the three additive primary colors: red, green, and blue (RGB). EX: 1. Stage Lighting 2. Computer/TV pixels Sketch using color

Printers & CMYK process The CYMK process is another name for adding pigments to make color. The three pigments, cyan, magenta, yellow, and black are added in different proportions.

Exit questions 1. 2. 3. 4. 5. 6. 7. 8. What is white light in terms of the other colors? What are three additive colors? RGB What color of visible light has the least energy? The most energy? RED What are three subtractive colors? Magenta, Yellow, Cyan A green object reflects green light (T/F). And the remaining A blue object absorbs red & yellow (T/F). colors of ROYGBIV Energy Low Energy A yellow object reflects red light. High (T/F). A white object absorbs red light (T/F). A white object reflects ALL of ROYGBIV which together makes white light.