Patent ID: 8427757

Claim:
An image pickup apparatus comprising: a zoom lens; and an image pickup element having an image pickup surface that converts an image formed by the zoom lens into an electrical signal, wherein the zoom lens consists of, in order from the object side, a first lens unit having a positive refractive power in which a reflecting surface that deflects the optical path is provided, a second lens unit having a negative refractive power, and a rear lens unit having a positive refractive power, wherein the rear lens unit comprises, in order from the object side, a third lens unit and a fourth lens unit, wherein an aperture stop is provided between the second lens unit and the fourth lens unit, wherein during zooming from the wide angle end to the telephoto end, the first lens unit is kept stationary, the second lens unit moves in such a way as to be located closer to the image side at the telephoto end than at the wide angle end, and the distances between the lens units change, wherein the second lens unit comprises a plurality of negative lenses, wherein the negative lens located closest to the object side among the plurality of negative lenses is a first negative lens, and wherein the following conditional expressions (a), (b), and (c-1) are satisfied: 3.3<β 2T /β 2W <34 (a), −0.14< f 2G1N /f T <−0.001 (b), and 0< D 2G1N /f T <0.02 (c-1), where β 2T is the lateral magnification of the second lens unit at the telephoto end, β 2W is the lateral magnification of the second lens unit at the wide angle end, f 2G1N is the focal length of the first negative lens in the second lens unit, D 2G1N is the thickness of the first negative lens in the second lens unit on the optical axis, and f T is the focal length of the entire zoom lens system at the telephoto end.