Patent ID: 9726867
Date: 2017-08-08
CPC Classifications: G02B

Claim:
1. A variable magnification optical system consisting of: a first lens group having negative refractive power: a stop; and a second lens group having positive refractive power in this order from an object side, and the variable magnification optical system being configured to change magnification by changing a distance between the first lens group and the second lens group in an optical axis direction and to perform correction of the position of an image plane necessitated by the change in magnification by moving the first lens group in the optical axis direction, wherein the first lens group comprises, in this order from the object side, an L wherein the second lens group comprises an L wherein the C wherein the following conditional expressions (1) and (2) are satisfied: Rf11: a curvature radius of an object-side surface of the L Rf12: a curvature radius of an object-side surface of the L νdave1: an average of Abbe numbers for d-line of all negative lenses arranged toward the object side of the positive lens constituting the C