What defines a reflecting telescope?

A reflecting telescope is defined by its use of mirrors to gather and focus light. This design takes advantage of the reflective properties of mirrors, which can be shaped to create a specific focal path. The primary mirror collects light from distant objects and reflects it to a focal point, where an eyepiece or camera can be placed to view or capture the image. This configuration allows for the construction of larger telescopes compared to refracting telescopes, which use lenses.

Mirrors can be made larger, since they can be supported from behind, and they do not suffer from chromatic aberration like lenses do, making them particularly effective for observing a wide range of celestial objects. The design leads to improved image clarity and brightness, which are crucial for astronomical observations. Other options do not reflect the fundamental principles of defining a reflecting telescope.