In imaging using a linear log sensor and also an auxiliary light source, an image pickup apparatus capable of executing imaging for obtaining a good contract for a main photographic subject is provided. In an image pickup apparatus 1, an image pickup device 4 having a linear conversion operation and a logarithmic conversion operation, an irradiation unit 6 for irradiating light at time of picking up an image of a photographic subject, and an inflection point changing unit 25, when imaging using the irradiation unit 6, for changing the position of an inflection point which is a boundary between a linear area and a logarithmic area so as to position a brightness distribution of the main photographic subject in the linear area of an output signal of the image pickup device 4 are installed.