1. An image pickup apparatus, comprising: an image pickup device including a plurality of pixels which have a plurality of different photoelectric conversion characteristics different from each other on each side of an inflection point; a light shielding member for shading the pixels; an image pickup control section for controlling an image pickup operation of the image pickup device, the image pickup control section having a reset mode in which the image pickup control section resets the pixels of the image pickup device to predetermined first and second potentials different from each other with the pixels of the image pickup device shaded by the light shielding member and thereafter outputs imaged data; and an image processing section for image processing the imaged data outputted from the image pickup device, wherein the image processing section, including: an inflection point data generation section for generating an inflection point data which indicates inflection points of the photoelectric conversion characteristics of the pixels of the image pickup device based on the imaged data outputted in the reset mode; and an inflection point correction section for executing a correction operation for correcting differences between an inflection point of a standard photoelectric conversion characteristic and the inflection points of the photoelectric conversion characteristics of the pixels of the image pickup device based on the inflection point data.