ZOOM LENS, OPTICAL INSTRUMENT, AND MANUFACTURING METHOD FOR ZOOM LENS

WIPO Patent Application WO/2017/057662

A1

The present invention comprises, arranged in the following order from the object side, a first lens group (G1) having a positive refractive power, a second lens group (G2) having a negative refractive power, a third lens group (G3) having a positive refractive power, a fourth lens group (G4) having a negative refractive power, and a fifth lens group (G5) having a positive refractive power, wherein when zooming from a wide angle end state to a telephoto end state, all of the first to fifth lens groups (G1 to G5) move in the direction of the optical axis, wherein at least a part of the fourth lens group (G4) constitutes a focusing lens group which moves in the optical axis direction when focusing wherein the first lens group (G1) is composed of two lenses and satisfies the following conditional expression: 0.30