Patent ID: 8873154
Filing Date: 2014-10-28
Classification: G02B

Abstract:
1. A tele-side converter lens, to be removably mounted to an object side of a master lens so as to increase a focal length of an entire system, the tele-side converter lens comprising, in order from the object side to an image side, a first lens unit having a positive refractive power and a second lens unit having a negative refractive power, the first lens unit and the second lens unit being formed with a largest air interval therebetween, wherein: the first lens unit includes one or two positive lenses; the second lens unit includes one negative lens and one or two positive lenses; and the following conditional expressions are satisfied: where νd νd νd νd νd f NdG β represents a magnification of the tele-side converter lens, provided that a combined Abbe constant νdi of an i-th lens unit is expressed by the following equation: where m represents a number of lenses constituting the i-th lens unit, and fik and νik respectively represent a focal length and an Abbe constant of a k-th lens from the object side in the i-th lens unit.