A fisheye lens is a type of ultra-wide-angle lens that captures a wide field of view, typically around 180 degrees or more. This lens creates a distinctive, spherical distortion, making images appear curved at the edges. It is commonly used in photography and videography to achieve dramatic effects and to capture expansive scenes. Fisheye lenses are popular in various fields, including landscape photography, architecture, and sports photography. They allow photographers to include more of the scene in a single shot, making them ideal for tight spaces or when trying to convey a sense of depth and perspective.