1. A video camera apparatus, comprising: (A) image sensing means for photoelectrically converting an object image formed on an image sensing plane to produce and output an image signal; (B) area setting means for setting a detecting area for detecting a photographing state of the object image on said image sensing plane; (C) detecting means for detecting a variation of a feature of the object image on the basis of the image signal corresponding to said detecting area in a first period of time; (D) control means for controlling said area setting means in a second period of time longer than said first period of time in accordance with an output of said detecting means and for causing the position and size of said detecting area on said image sensing plane to follow the variation of the feature of said object image, to independently change said detecting area in the first period; (E) focus detecting area setting means for setting a position of a focus detecting area in the second period of time at a center of said detecting area on said image sensing plane on the basis of the output of said detecting means; and (F) focus control means for adjusting a focus condition in the second period on the basis of the image signal corresponding to said focus detecting area.