A twin-lens reflex camera (TLR) is a type of camera with two objective lenses of the same focal length. One of the lenses is the photographic objective or "taking lens" (the lens that takes the picture), while the other is used for the viewfinder system, which is usually viewed from above at waist level.

A twin lens reflex camera, also known as TLR camera, features two lenses stacked one above the other. The top lens is the viewing lens used for composing the image, while the bottom lens, connected to the film, captures the actual photograph. These lenses are mechanically coupled, allowing for simultaneous focusing and image capture.