Porro prism telescope

A Porro prism telescope uses a pair of prisms arranged in a zigzag pattern to invert and revert the image, providing a wide field of view with good depth perception. Light enters the front, reflects internally within the prisms, and emerges with the image correctly oriented for the viewer. This design results in a compact, lightweight, and affordable instrument that offers sharp, bright images—commonly used in binoculars and some mid-range telescopes. The Porro prism arrangement enhances image quality and field of view, making it a popular choice for terrestrial and astronomical observations.