A solid-state imaging device is provided that includes a pixel array section having pixels which detect a physical quantities that are arranged in two dimensions of a matrix; an Analog-Digital (AD) converting section that performs AD conversion for a plurality of channels of analog pixel signals which are read-out from the pixel array section; and a control section that sets quantized units AD-converted by the AD conversion section according to a gain setting of the unit pixel signal, where the control section determines a grayscale number of digital outputs AD-converted for at least one channel of the unit pixel signals according to the gain setting of the pixel signal.