Patent ID: 8654447

Claim:
A zoom lens comprising, in order from the object side: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; a fourth lens unit having a negative refractive power; and a fifth lens unit having a positive refractive power, wherein during zooming from the wide angle end to the telephoto end, the first lens unit is fixed, the second lens unit moves toward the image side, the third lens unit moves toward the object side, the fourth lens unit moves, and the fifth lens unit is fixed, the first lens unit comprises a reflecting member that bends the optical path by 90 degrees, the entirety of or at least a part of the fifth lens unit is shifted in directions transverse to the optical axis to stabilize a picked-up image when the optical system vibrates, and the zoom lens satisfies the following conditional expressions (1) and (2): 0.28<1−β 5 <1.0 (1), and −2.2 <f 4 /f w <−1.0 (2), where β 5 is the image magnification of the fifth lens unit in the entire zoom range with the zoom lens being focused on an object point at infinity, f 4 is the focal length of the fourth lens unit, and f w is the focal length of the entire zoom lens system at the wide angle end.