The present disclosure relates to zoom lenses and optical devices using the same. A zoom lens may include in order from an object side to an image side: a first lens group, a second lens group, a third lens group, a fourth lens group; and a fifth lens group. The zoom lens may satisfy the following conditions: −2.28≤f2/fw′≤−1.08, and 0.15≤TTL/(BFL*fw′)≤0.45, wherein f2 denotes a focal length of the second lens group, fw′ denotes a focal length of the zoom lens at a wide angle end, TTL denotes a total track length of the zoom lens, and BFL denotes a back focal length of the zoom lens.