| 摘要 |
<p>A variable magnification optical system consists of first lens group having negative refractive power and second lens group having positive refractive power, which are in this order from an object side, and a distance in an optical axis direction between the first lens group and the second lens group changes when magnification is changed. The second lens group consists of a positive sixth lens, a negative seventh lens, a positive eighth lens, and a cemented lens composed of a negative ninth lens and a positive tenth lens cemented together, which are in this order from the object side, and all of the three positive lenses, which are the sixth lens, the eighth lens and the tenth lens, are double-convex lenses. A predetermined formula is satisfied.</p> |
