US Patent 7903169 Photographic device and control method therefor

There is disclosed a photographic device that uses an image sensor and an electronic viewfinder. When a release button is pressed halfway, an aperture value, an electronic shutter speed and a photosensitivity are decided based on the present subject brightness to provide a proper exposure value for photographing a still image. So long as the release button is kept being pressed halfway, a timing generator drives the image sensor to shoot video images at a frame rate of 20 Hz, and the aperture value decided for still image photography is fixed, whereas the electronic shutter speed and the photosensitivity are adjusted according to the subject brightness by use of an aperture-priority type video program. When the release button is pressed to the full, an exposure for a still image is done with the fixed aperture value.