Patent ID: 8432464

Claim:
An image pickup apparatus comprising: a zoom lens; and an image pickup element having an image pickup surface for converting an image formed by the zoom lens into an electrical signal, wherein the zoom lens comprises, in order from the object side to the image side, a first lens unit having a positive refracting power including a reflecting member having a reflecting surface that deflects the optical path, a second lens unit having a negative refracting power, and a rear lens unit group having a positive refracting power as a whole and comprising, in order from the object side, a third lens unit, a fourth lens unit, and a fifth lens unit, the zoom lens comprises an aperture stop disposed between the second lens unit and the fourth lens unit, 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 that it is located closer to the image side at the telephoto end than at the wide angle end, and the distances between the lens units change, the first lens unit comprises, in order from the object side to the image side, a negative lens component, the reflecting member, and a rear sub-lens unit comprising a first positive lens element and a second positive lens element, and the following conditional expressions (1), (2), and (3) are satisfied: 7 <f T /f W <30 (1), 0.5 <f W /IH< 1.38 (2), and 16.5<|ν dp1 −ν dp2 |<80 (3), where f T is the focal length of the entire zoom lens system at the telephoto end, f w is the focal length of the entire zoom lens system at the wide angle end, IH is the highest image height in an effective image pickup area on the image pickup surface, ν dp1 is the Abbe constant of the first positive lens element in the first lens unit with respect to the d-line, ν dp2 is the Abbe constant of the second positive lens element in the first lens unit with respect to the d-line, the term “lens component” refers to a lens member composed of a single lens element or a cemented lens component delimited by effective lens surfaces that are in contact with air, and the Abbe constant is defined as (n d1 −1)/(n F1 −n C1 ) with n d1 , n C1 , and n F1 being the refractive indices of the first or second positive lens element with respect to the d-line, the C-line, and the F-line respectively.