What type of telescopes are in a pair of binoculars?

• A. Refracting telescopes
• B. Radio telescopes
• C. Reflecting telescopes
• D. Compound telescopes

Answer: (C)

Binoculars contain two small telescopes used side by side to view distant objects. In most binoculars, light is gathered and focused with lenses, not mirrors, which means the optical system is refracting. The front lenses collect light and form an enlarged image that’s viewed through the eyepieces. Prisms inside the body simply rotate the image so it appears upright, but they don’t change the fundamental part of the system being lenses. Reflecting telescopes use mirrors to collect and focus light, which isn’t how standard binoculars are built. Radio telescopes are designed for radio waves, not visible light. A compound telescope combines lenses and mirrors in one system, but binoculars are typically two separate refracting units with prisms for orientation. So the type of telescope inside binoculars is a refracting telescope.