In this activity, students explore the nature of light, including the fact that it travels in straight lines, by building and using two visual tools. The first is a simple pinhole camera—a box with a pinhole opening. The second is a camera obscura—a tool of historical interest, particularly in the arts. The camera obscura, basically a pinhole camera with a lens, was a forerunner of the modern camera and allowed 17th- and 18th-century artists to make very accurate sketches of their subjects. During the activity, students will explore the operation of these simple instruments and will learn why, historically, the camera obscura was an important tool for many artists. The entire lesson will also serve as an introduction to the art of photography, which will be explored more fully in Activity 7.