A photoelectric conversion device includes a photoelectric conversion element to generate an image signal according to an intensity of light being input and circuitry. The circuitry obtains pixel values in dark time, respectively, for at least a first time and a second time. The second time is longer than the first time. The pixel values in dark time represent pixel values obtained when no light is input to the photoelectric conversion element. The circuitry obtains a subtraction between the pixel values for the first time and the pixel values for the second time. The circuitry detects a noise amount based on the subtraction. The circuitry determines at least one pixel having the detected noise amount that is equal to or greater than a predetermined first threshold value, as a defective pixel of the photoelectric conversion element.