Designed for exclusive use with PENTAX K-mount interchangeable-lens digital cameras, this unifocal, medium-telephoto lens features a large maximum aperture and a round diaphragm to produce a natural, beautiful bokeh (out-of-focus) effect, making it ideal for portrait, still life, or low light photography. Its front surface is treated with the PENTAX-original SP (Super Protect) coating, which repels dust, water, grease, and other substances that may adhere to the surface of the lens. Its outstanding performance and compact, lightweight design makes it an excellent choice for photographers of all levels.