Optical System and Camera Module

A camera module, comprising:

• an optical system, wherein the optical system comprises a first element group and a second element group, which are sequentially disposed from an object side to an image side along an optical axis, the first element group is configured for turning an optical path;
• the second element group is able to move to a first zoom point and a second zoom point in an direction along the optical axis, so that the optical system switches between a long-focus state and a short-focus state;
• the optical system satisfies 0.39<DL/DEFL<0.49, the DL is a movable stroke of the second element group, and the DEFL is a variation of an effective focal length of the optical system switching from the long-focus state to the short-focus state;
• and
• an imaging element, wherein the imaging element is configured for converting an optical image formed by the optical system into an electrical signal.