CPC G02B 15/143 (2019.08) | 19 Claims |
1. A zoom optical system comprising a first lens group, a second lens group, and a third lens group which are sequentially arranged from an object side to an image side, wherein:
the first lens group consists of three fixed lenses;
the second lens group consists of two movable lenses;
the third lens group consists of two movable lenses;
a magnification is adjusted according to movement of the second lens group;
a focus is adjusted according to movement of the third lens group;
a focal length at a maximum magnification is 13 mm or more; and
a f-number at the maximum magnification is 3.7 or less.
|