Image capturing device and image capturing method

An image capturing device which includes a single optical pickup system and an imaging element that has a first pixel group and a second pixel group respectively performing photoelectric conversion on light fluxes passing through different regions of the single optical pickup system, and which performs stereoscopic pickup used to generate a stereoscopic image composed of a first image and a second image from the first pixel group and the second pixel group, and plane pickup used to generate a third planar image as a planar image from the first pixel group and the second pixel group, the image capturing device comprising:

• light extinction unit reduces an amount of light which is incident to the imaging element from the optical pickup system;
• a diaphragm that is arranged in a light path which the light fluxes irradiated to the image sensor passes through;
• subject brightness acquisition unit that acquires subject brightness;
• and
• control unit that, in a case of the stereoscopic pickup, controls whether or not to reduce the amount of light which reaches the imaging element using the light extinction unit based on the subject brightness acquired using the subject brightness acquisition unit, and that, in a case of the plane pickup, causes a diaphragm value of the diaphragm to be greater than a diaphragm value in the case of the stereoscopic pickup.