Patent ID: 8654457
Filing Date: 2014-02-18
Classification: G02B

Abstract:
1. A wide-angle optical system comprising, in order from an object side to an image side: a front group; a stop; and a rear group, wherein the front group comprises, in order from the object side to the image side, the rear group comprises, in order from the object side to the image side, an opposite surface from the stop of each of a pair of lenses which are arranged at the both sides of the stop is a convex surface, and the wide-angle optical system satisfies the following conditional expressions: where νd3 is an Abbe number of the third lens, νd4 is an Abbe number of the fourth lens, νd5 is an Abbe number of the fifth lens, Ff is a focal length of the front group, Fr is a focal length of the rear group, F4 is a focal length of the fourth lens, and F5 is a focal length of the fifth lens.