A 135mm lens is a type of telephoto lens commonly used in photography. It has a focal length of 135 millimeters, which allows it to capture distant subjects with clarity while providing a shallow depth of field. This makes it ideal for portrait photography, as it can create a pleasing background blur, isolating the subject effectively. These lenses are often favored for their sharpness and ability to produce beautiful bokeh, the aesthetic quality of the out-of-focus areas in an image. Many photographers use 135mm lenses for events, wildlife, and sports photography, as they can bring distant subjects closer without distortion.