ZOOM LENS AND IMAGING APPARATUS

摘要

The zoom lens substantially consists of a positive first lens group fixed while changing magnification, a negative second lens group which moves from the object side to the image side while changing magnification, a positive third lens group which moves while changing magnification, and a positive fourth lens group which moves from the image side to the object side while changing magnification, and a positive fifth lens group fixed while changing magnification in this order from the object side. A floating system in which the third lens group and the fourth lens group move relative to each other while changing magnification is adopted. The image formation magnification rates of the combined lens group formed by the third lens group and the fourth lens group together and the second lens group simultaneously pass −1× point while changing magnification from the wide angle end to the telephoto end.

主权项

1. A zoom lens substantially consisting of:
a first lens group having a positive refractive power, which is fixed while changing magnification; a second lens group having a negative refractive power, which moves from the object side to the image side while changing magnification from the wide angle end to the telephoto end; a third lens group having a positive refractive power, which moves while changing magnification; a fourth lens group having a positive refractive power, which moves from the image side to the object side while changing magnification from the wide angle end to the telephoto end; and a fifth lens group having a positive refractive power, which is fixed while changing magnification; wherein the third lens group and the fourth lens group move relative to each other while changing magnification; image formation magnification rates of a combined lens group formed by combining the third lens group and the fourth lens group together and the second lens group simultaneously pass a −1× point when changing magnification from the wide angle end to the telephoto end; and conditional formula (1) below is satisfied:
(Dg34max−Dg34min)/fw>2.5   (1), where fw: the focal length at the wide angle end, Dg34max: the maximum value of the distance between the third lens group and the fourth lens group while changing magnification, and Dg34min: the minimum value of the distance between the third lens group and the fourth lens group while changing magnification.