Patent ID: 6222681
Filing Date: 2001-04-24
Classification: G02B

Abstract:
A zoom lens system capable of performing macro-photography, the system comprising, in the order from an object side:a first lens unit that has positive optical power and is fixed during zooming;a second lens unit that has negative optical power and is movable along an optical axis of the system during zooming;a third lens unit that has positive optical power and is fixed during zooming; anda fourth lens unit that has positive optical power and is movable along the optical axis during zooming,wherein said second lens unit is movable along the optical axis toward the object side for macro-focusing,wherein the following condition is fullfilled: ##EQU8##wheref.sub.1,2 : combined focal length of the first and second lens units in the shortest focal length condition;f.sub.W : focal length of the entire zoom lens system in the shortest focal length condition.