An apparatus includes a pixel unit including a plurality of pixels arranged in a plurality of rows and each including a quench element of which a control node a signal defining a start and an end of an exposure period is input to and a photodiode connected to the quench element, a scan unit that scans the pixel unit by performing processing of reading signals of the pixels, processing of starting the exposure period, and processing of ending the exposure period on the plurality of rows sequentially in units of one row or two or more rows, and a control unit that outputs a synchronization signal to the scan unit to control a timing of the reading processing, wherein at least one of a timing of the start processing and a timing of the end processing is controlled by another control signal different from the synchronization signal.