Patent ID: 8917456

Claim:
A medium telephoto lens which substantially consists of a first lens group having positive refractive power and a second lens group in order from an object side, wherein the first lens group substantially consists of a positive 1-1 lens with a convex surface toward the object side, a positive 1-2 lens with a convex surface toward the object side, a positive 1-3 lens with a convex surface toward the object side; a negative 1-4 lens with a concave surface toward an image side; an aperture stop, a negative 1-5 lens with a concave surface toward the image side, a positive 1-6 lens with a convex surface toward the object side, and a positive 1-7 lens with a convex surface toward the object side, in this order from the object side; the 1-3 lens and the 1-4 lens are cemented to each other and the 1-5 lens and the 1-6 lens are cemented to each other; the second lens group substantially consists of a negative 2-1 lens with a concave surface toward the image side and a positive 2-2 lens with a convex surface toward the object side; and only the first lens group moves in the optical axis direction while focusing.