Patent ID: 9638892
Date: 2017-05-02
CPC Classifications: G02B

Claim:
1. A rear conversion lens, comprising: a chassis including two opposite ends, the chassis including light-transmitting holes on the ends, respectively; a first coupler configured to detachably couple one of the ends of the chassis; a second coupler configured to detachably couple the other end of the chassis; and an optical system including a first lens group, a second lens group, and a third lens group arranged in the chassis in this order from an object side, the first lens group having a negative compound focal length, the second lens group being configured to correct a spherical aberration, the third lens group being configured to form an image, wherein the first lens group includes first three-bonded lenses, the second lens group includes a concave lens, a convex lens, and second three-bonded lenses in this order from the object side, and the third lens group includes a convex lens.