Patent ID: 8203795

Claim:
A macro-lens system comprising: a first lens group which has a positive refractive power and is fixed during focusing; a second lens group which has a negative refractive power and is moved during focusing; a third lens group which has a positive refractive power and is fixed during focusing; a fourth lens group which has a positive refractive power and is moved during focusing; and a fifth lens group which has a negative refractive power, wherein the first, second, third, fourth, and fifth lens groups are arranged in order from an object side to an image side, and the macro-lens system satisfies the expression: 0.5 ⁢ < _ ⁢ f 3 f ⁢ < _ ⁢ 0.9 wherein f 3 denotes a focal length of the third lens group, and f denotes a total focal length of the macro-lens system.