A first imaging unit images angle-of-view mark light of each of other television cameras. An image compositing unit generates a virtual angle-of-view mark image and a virtual angle-of-view frame image as a virtual angle-of-view image showing an imaging angle of view of each of the other television cameras in an imaging angle of view of the host television camera based on the angle-of-view mark light of each of the other television cameras. The image compositing unit generates a composite image by compositing the virtual angle-of-view mark image and the virtual angle-of-view frame image with a video image. The composite image is displayed on a lens monitor of a lens device that is detachable from a camera body.