Patent ID: 8785833

Claim:
An image pickup system comprising: an image pickup device in which a plurality of pixels for performing photoelectric conversion are arrayed in a two-dimensional shape in units of horizontal lines; an image pickup control unit configured to set a predetermined exposure period to be longer than a period required for readout of all horizontal lines and cause the image pickup device to sequentially start exposure of the image pickup device for each of the horizontal lines, and, after causing the image pickup device to start exposure of a last horizontal line, cause the image pickup device to sequentially perform readout for each of the horizontal lines on which the predetermined exposure period elapses from the exposure start to thereby control the image pickup device such that an all line exposure period in which all the horizontal lines are simultaneously exposed and a non-all line exposure period other than the all line exposure period in a period in which any one of the horizontal lines is exposed are generated; a light source configured to emit illumination light emitted to an object which is a target of image pickup by the image pickup device; a light source driving unit configured to drive the light source to be capable of adjusting a light amount of the illumination light; and a light adjustment controlling unit configured to control the light source driving unit to increase or decrease, in a first light adjustment mode, while maintaining a light amount of the illumination light in a first period during the all line exposure period at a predetermined level, a light amount of the illumination light during a second period including the all line exposure period other than the first period and the non-all line exposure period compared with an immediately preceding second period.