With a large maximum aperture of f12 this is the fastest 85mm telephoto lens in its class with a large maximum aperture of f12 this is the fastest 85mm telephoto lens in its class one aspherical lens element and two high refraction elements give sharp images with little flare even at the maximum aperture the floating system corrects coma for high image quality focal length and maximum aperture 85 mm f12 lens construction 8 elements in 7 groups diag