A camera a has an image sensor; an exposure controller that conducts a main exposure and a dark exposure, in order, when a long-exposure shooting is carried out; an image signal processor that processes image-pixel signals that are generated by the main exposure and are read from the image sensor; and a noise reduction processor that reduces dark current components in the image-pixel signals on the basis of dark current components in the dark exposure. The exposure controller operates the image sensor for heating between the main exposure and the dark exposure.