OPTICAL SYSTEM AND IMAGING DEVICE

WIPO Patent Application WO/2020/213337

A1

An optical system according to the present disclosure is provided with, in the following order from the object side to the image surface side: a first lens group that has a positive refractive power as an entire group, and includes a first negative meniscus lens and a second negative meniscus lens in this order from the object side to the image surface side; and a second lens group that has a positive refractive power as an entire group and moves as an entire group on the optical axis during focusing, with the surface thereof closest to the object side having a shape protruding toward the object side. The optical system satisfies the following conditional expression.　(1): 0