An image photographing apparatus and method, and more particularly, an image photographing apparatus and method that may divide each unit sensor of an image sensor into a high-sensitivity sensor and a low-sensitivity sensor and sense an incident optical signal using the high-sensitivity sensor and the low-sensitivity sensor. The image photographing apparatus may include a light reception unit receiving an optical signal, a sensor unit sensing the optical signal, which is incident to a pixel region, using a plurality of sensors with different sensitivity and converting the sensed optical signal into a plurality of electrical signals, and a signal extraction unit extracting the quantity of accumulated electric charge for the optical signal, which was sensed by each of the sensors, with reference to each of the electrical signals.