1. An image pick-up apparatus to pick up an image of an object, the image pick-up apparatus comprising: an image pick-up unit having a light receiving surface exposed to receive light from the object to carry out photo-electric conversion, and configured to output one or more pixel values obtained as the result of the photo-electric conversion; an evaluation unit configured to evaluate whether the pixel value is within a predetermined range; a control unit configured to control, in pixel units, exposure time with respect to the light receiving surface on the basis of evaluation result by the evaluation unit, wherein when the evaluated pixel value is not within the predetermined range, the control unit controls the exposure time with respect to a pixel of the light receiving surface corresponding to said pixel value, thereby changing the pixel value to be within the predetermined range, and wherein the control unit comprises: plural reflection mirrors rotatably configured to reflect the light onto the light receiving surface; and a rotational control section configured to control rotations of the respective plural reflection mirrors on the basis of evaluation result by the evaluation unit to control exposure time with respect to the light receiving surface in pixel units; wherein the evaluation unit comprises: a memory unit configured to store the pixel value that the image pick-up unit outputs; and a movement judging section configured to compare the pixel value of a selected pixel that the image pick-up unit outputs and the pixel value stored in the memory unit corresponding to the selected pixel value to thereby judge movement of the selected pixel; and wherein the control unit controls the exposure time with respect to the selected pixel of the light receiving surface on the basis of judged movement of the pixel value of the selected pixel.