TL/DR: A fisheye lens captures a wide, hemispherical view, creating a distinctive, curved image often covering 180° or more. It’s used in surveillance for full-area coverage without needing multiple cameras.
A fisheye lens is an ultra-wide-angle lens designed to capture a broad, hemispherical view, typically covering 180 degrees or more. Its curved shape creates a distinctive distortion that bends straight lines toward the edges, producing a “bubble” effect. This lens type is commonly used in surveillance, action cameras, and photography to cover large areas with a single camera, reducing the need for multiple angles or additional equipment.
A fisheye lens works by using a highly curved optical design to capture an ultra-wide, panoramic view, bending light toward the edges of the frame. The lens elements are arranged to spread out the image across a wide field, typically up to 180 degrees or more, which causes straight lines to appear curved, especially near the edges.
This curvature allows the lens to compress a large area into a single frame, providing full coverage of a scene without blind spots. In surveillance, this enables a single camera with a fisheye lens to monitor an entire room or large area, capturing everything in one wide-angle shot.
A fisheye camera is commonly used in surveillance for monitoring large spaces like retail stores, warehouses, or office lobbies. Its ultra-wide, 180-degree lens provides a full view of the area with just one camera, reducing the need for multiple devices to cover the same space. In retail, for example, a fisheye camera can monitor customer activity across aisles and reduce blind spots, improving loss prevention and security. In public spaces, it offers a comprehensive view for crowd management and safety without requiring extensive camera setups.