1. A photographing device comprising: two or more lenses, each of the two or more lenses having different view angles; and a processor configured to at least: control detecting of one or more subjects based on images acquired using the lenses; control determining, based on images acquired using the lenses, whether a second subject approaches a view angle for a first lens within which a first subject, but not the second subject, is detected; and control generating of a notification signal based on determining that the second subject approaches the view angle for the first lens.