what is a telephoto camera

A telephoto camera is a type of camera lens that has a long focal length and allows photographers to take pictures of subjects that are further away. The physical length of the lens is shorter than its focal length, which is achieved by incorporating a second set of elements close to the film or sensor plane that extends the cone of light so that it appears to have come from a lens of much greater focal length. Telephoto lenses can be zoom lenses or prime lenses, and they need many pieces of glass inside, which often makes them large, heavy, and expensive. Nowadays, it is common to have telephoto lenses on the rear of a phone camera, which enables the camera to take clear photos from further away from the subject. The telephoto lens on a phone camera is a vital part of the blurred background, bokeh effect, and portrait mode.