A camera system at least including: a MOS imaging device at least having a pixel section having a plurality of pixels two-dimensionally arrayed in row and column directions, each having a photoelectric conversion section for generating electrical signal corresponding to a quantity of incident light, an accumulation section for accumulating signal generated at the photoelectric conversion section, a transfer switch means for controlling transfer of signal from the photoelectric conversion section to the accumulation section, a reset switch means for resetting signal of the photoelectric conversion section, an amplification section for outputting a voltage value corresponding to signal of the accumulation section, and a select switch for selecting output of the amplification section, wherein an exposure period is determined by simultaneously resetting signals of the photoelectric conversion section for all pixels and effecting signal transfer from the photoelectric conversion section to the accumulation section after a predetermined time, and readout of signal from the pixels is sequentially effected at later time; and an incident light quantity suppressing means for suppressing the quantity of light incident to the MOS imaging device during read operation of signal from each pixel of the MOS imaging device.