Catadioptric systems are optical devices that combine lenses and mirrors to form images. These systems utilize both refraction, which is the bending of light through lenses, and reflection, which is the bouncing of light off mirrors. This combination allows for compact designs and improved image quality, making them popular in various applications, including telescopes and cameras. One common example of a catadioptric system is the Schmidt-Cassegrain telescope. This type of telescope uses a spherical mirror and a corrector lens to gather light and produce clear images of celestial objects. Catadioptric systems are valued for their versatility and ability to minimize optical aberrations.