Light, Mirrors, and Lenses

Chapter 4

Properties of Light

Section 1

• Light is a wave that carries energy; a light source emits a countless number of light rays that travel in all directions.

Properties of Light

• The material through which a wave travels is called a medium.

• Light is an electromagnetic wave that does not need a medium in which to travel.

• For the eyes to see an object, light must strike the object and bounce off, a process called reflection.

• Materials that let no light pass through them are opaque.

• Transparent materials let almost all light pass through them.

• Materials that let some, but not all, light pass through them are translucent.

• White light is composed of different wavelengths, which have colors ranging from red to violet.

• Objects appear to have color because they absorb some light waves and reflect others; an object appears the color of the light it reflects.

• Light colors: the color you see is the color your eye interprets from the mixture of red, blue, or green light.

• The primary colors of light are red, blue, and green.

• Pigments are colors you see in objects – paint, markers, dyes, etc. (Color Wheel)

• Pigment colors: the color you see is the color your eye interprets from waves reflected from the pigment.

• The primary pigment colors are yellow, magenta, and cyan.

Madame X by

John Singer Sergeant

Painting with Primary Colors

Light vs. Pigment