光学系、光学装置、および光学系の製造方法

Japanese Patent JP5224192

B2

PROBLEM TO BE SOLVED: To provide an optical system having a good optical performance.SOLUTION: In a wide angle lens WL composed of a first lens group G1 having a negative refractive power and a second lens group G2 having a positive refractive power in order from an object side along an optical axis, the first lens group G1 is fixed, and the second lens group G2 moves at the time of focusing from an infinite-distance object to a finite-distance object. When a focal length of the first lens group G1 is defined as f1, a focal length of the second lens group G2 is defined as f2, and a focal length of the wide angle lens WL in an infinite focusing state is defined as f, conditional expressions represented by 0.10<(-f1)/f2<2.50 and 0.20