1. A digital camera comprising: an image sensor which captures an object image via a photographing lens; a display device which displays a through-the-lens display of an object image that is captured by said image sensor; an autofocus adjuster that performs an autofocusing operation in an autofocusing mode by detecting a focal state based on said object image captured by said image sensor and brings a specified object image into an in-focus state, based on the detected focal state, by moving a focal-adjusting lens group of said photographing lens in the optical axis direction thereof; a lens detector which detects whether or not said photographing lens is a specific-function photographing lens, said specific-function photographing lens being configured such that a manual operation, in which said focal adjusting lens group is manually moved, can be performed independently of said autofocus adjuster, by a manual operation member that is provided on said specific-function photographing lens, while said digital camera is in the autofocusing mode, said manual operation overriding said autofocusing operation without requiring said digital camera to be switched to a manual mode; and a distinguishing-display controller which carries out image processing on at least a part of said specified object image, upon said focal-adjusting lens group being moved to an infocus position by said auto focus adjuster and said lens detector detecting that said photographing lens is said specific-function photographing lens, wherein said distinguishing-display controller displays said specified object image on said display device in a manner that distinguishes said specific object image from other object images.