Variable power optical assembly, optical device, and variable power optical assembly fabrication method

Abstract

Comprising, in order from an object side: a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; a third lens group G3 having positive refractive power; a fourth lens group G4; a fifth lens group G5; and a sixth lens group G6; upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group G1 and the second lens group G2, a distance between the second lens group G2 and the third lens group G3, a distance between the third lens group G3 and the fourth lens group G4, a distance between the fourth lens group G4 and the fifth lens group G5, and the distance between the fifth lens group G5 and a sixth lens group G6 being varied; and a predetermined conditional expression being satisfied, thereby providing a variable magnification optical system which has a high variable magnification ratio, is compact in size and has high optical performance, an optical apparatus, and a method for manufacturing the variable magnification optical system.

1 . A variable magnification optical system comprising, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group; a fifth lens group; and a sixth lens group;
 upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group, a distance between the second lens group and the third lens group, a distance between the third lens group and the fourth lens group, a distance between the fourth lens group and the fifth lens group, and a distance between the fifth lens group and the sixth lens group being varied; and   the following conditional expressions being satisfied:
   5.500< f 1/ fw< 10.200 
   0.057<(− f 2)/ ft< 0.200
 
   where fw denotes a focal length of the variable magnification optical system in the wide-angle end state, ft denotes a focal length of the variable magnification optical system in the telephoto end state, f1 denotes a focal length of the first lens group, and f2 denotes a focal length of the second lens group.   
     
     
         2 - 30 . (canceled)