Both telescopes and binoculars magnify faraway objects to make them easier to see. To magnify is to make something look bigger. People use only one eye to look through a telescope, but they use both eyes to look through binoculars. Using both eyes makes faraway objects look more real.

How Binoculars Work

Most binoculars are made up of lenses and prisms. Lenses are circles of curved glass. Prisms are pieces of glass with several flat sides. The lenses and prisms change the direction of the light going through them. This creates the image of the object being viewed.

When light enters binoculars, it passes through a lens, called an object lens, in each side. Then the light reflects off two prisms in each side. Finally, the light passes through eyepieces into the eyes. The prisms help to direct the light from the object lenses to the eyepieces. Because of the prisms, the object lenses can be farther apart than the eyepieces are. Lenses in the eyepieces work together with the object lenses to make objects look bigger. A ring located between the eyepieces lets the user adjust the focus of the binoculars. Focusing makes objects look clearer.

How Binoculars Are Used

There are different strengths of binoculars. High-powered binoculars can make faraway objects look six, eight, or even 10 times bigger than they really are. Such binoculars are often used for watching birds and wild animals. Low-powered binoculars can make objects look three times bigger. They are handy for watching a play or a concert in a theater.

The size of the lenses is important, too. Larger lenses allow more light to enter the binoculars. This makes them work better at night or in dim light. However, larger lenses are also heavier. This makes the binoculars harder to carry and harder to hold steady. Smaller lenses might not be best for night viewing, but they are easy to hold and to carry.