A telephoto lens is a type of low distortion lens that has a long focal length, which allows the photographer to capture distant subjects in greater detail. These lenses are commonly used in sports, wildlife, and portrait photography, among other types of photography. The focal length of a telephoto lens is typically longer than the standard lens. Some advantages of using a telephoto lens include: Ability to capture distant subjects in greater detail Ability to isolate the subject from the background and create a shallow depth of field Ability to compress perspective, which can create a unique look in photographs Some common uses of telephoto lenses include: Sports photography, to capture athletes in action from a distance Wildlife photography, to capture animals without disturbing them Portrait photography, to create a shallow depth of field and isolate the subject from the background Landscape photography, to compress perspective and create a unique look in photographs When choosing a telephoto lens, it's important to consider factors such as focal length, aperture, image stabilization, and lens mount compatibility with your camera.