1. An imaging system for capturing images including a same object using a plurality of image capturing apparatuses capable of communicating with each other, the imaging system comprising: at least one image capturing apparatus of the image capturing apparatuses transmits captured image data which is cut-out of a first captured image including an in-focus position, wherein the transmitted image also includes the in-focus position, to another image capturing apparatus among the image capturing apparatuses, and each of the image capturing apparatuses determines each depth of field by using signals from an image area located within a second captured image, wherein the image area is an area selected from the second captured image on the basis of a correlation with the transmitted image, wherein the image area shows the in-focus position of the first captured image within the second captured image.