An electronic imaging apparatus includes a zoom optical system having, in order from the object side, a first lens unit with negative power and a second lens unit with positive power, in which lens components having refracting power in the first lens unit are only a single biconcave negative lens element located at the most object-side position and a positive lens component located at the most image-side position; an electronic image sensor placed on the image side of the zoom optical system; and an image processing section electrically processing image data obtained by the electronic image sensor to change the shape thereof. The zoom lens system satisfies the following conditions in focusing of a nearly infinite object point: 0.85