Exemplary embodiments are directed to dual camera autofocusing in digital cameras with error detection. An auxiliary lens and image sensor shares a housing with a main lens and image sensor which together act as a range finder to determine the distance to a scene. Scene distance is used in combination with contrast-detection autofocus to achieve maximum sharpness in the image. Errors in distance determination may be found and corrected using a comparison of data collected from the auxiliary lens and main lens.