An imaging apparatus comprises a plurality of pixels, a driving unit configured to successively reset signal charges stored in a photoelectric conversion unit at every predetermined line and successively read out a signal based on the signal charges at every predetermined line, and a control unit. The control unit has a first mode in which a starting readout line of the pixels is fixed and a second mode in which the starting readout line of the pixels is changeable based on input control information. The control unit changes a reset timing of the pixels of the starting readout line in the second mode so as to cause a second charge storage period to be less or equal to a first charge storage period in the second mode.