The Zeiss 140mm f2.8 Sonnar is a short telephoto lens for the Contax 645 system roughly equivalent to an 85mm lens in 35mm format. This ideal portrait focal length combines with the fast f2.8 aperture to create a powerful tool for selective focus, providing noticeably shallower depth of field than similar lenses such as the popular Zeiss 150mm f4 Sonnar for the Hasselblad V System.