Patent ID: 8824057

Claim:
A telephoto zoom lens system comprising: a first lens group having a positive focal length; a second lens group having a negative focal length; a third lens group having a positive or negative focal length; a fourth lens group having a positive focal length; and a fifth lens group for performing hand shake compensation by moving a portion of the fifth lens group perpendicularly to an optical axis, wherein, during zooming, the first and fifth lens groups are fixed and the second, third, and fourth lens groups move, the third or fourth lens group is a focusing lens group, and the following inequalities are satisfied: - 0.25 ≤ 1 2 ⁢ ( f wide f 1 ⁢ ⁢ AFwide + f tele f 1 ⁢ ⁢ AFtele ) ≤ 0.1 and ⁢ - 3.5 ≤ f + , max f - , min ≤ - 1.7 , wherein f +,max is the focal length of the lens group having the longest positive focal length of the second to fourth lens groups moving during zooming, f −,min is the focal length of the lens group having the shortest negative focal length of the second to fourth lens groups moving during zooming, f 1AFwide is the focal length at the wide angle position from the first lens group to the focusing lens group, f wide is the focal length at the wide angle position of the telephoto zoom lens system, f 1AFtele is the focal length at the telephoto position from the first lens group to the focusing lens group, and f tele is the focal length at the telephoto position of the telephoto zoom lens system.