| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical system of a large diameter that has various aberrations excellently corrected to obtain an excellent image quality over an entire screen, attains reduction in size of a product, and is suitable for an interchangeable lens. ! SOLUTION: An optical system comprises, in order from an object side, a first lens group G1, and a second lens group G2 having positive refractive power. The first lens group comprises, in order from the object side, a first lens group front group G1A having negative refractive power and a first lens group rear group G1B having positive refractive power which are spaced at the longest air distance on an optical axis in the first lens group G1. A surface on a most image surface I side of the first lens group front group G1A is configured to have a concave surface directed to the image surface I side, and a surface on the most object side of the first lens group rear group G1B is configured to have the concave surface directed to the objet side, |
