There is provided a lens system includes a first optical system and forms an intermediate image, which has been formed inside the first optical system by light from an input side, into a final image. The first optical system includes a first subsystem, with the first subsystem including a first lens that is disposed at a position closest to the intermediate image on the input side and moves during focusing and a second lens that is disposed at a position closest to the intermediate image on the output side and moves during focusing.