An image pickup system comprises an image pickup portion that outputs an electric signal obtained from a plurality of pixels by photoelectric conversion as image information a transmission portion that transmits the image information outputted by the image pickup portion to outside a reception portion that receives a synchronization signal that is transmitted periodically from outside calculation means that carries out processing to perform a predetermined calculation on a period of the synchronization signal that the reception portion receives and a transmission control portion that controls the transmission portion based on a second synchronization signal that takes a value that is based on a calculation result of the calculation means as a period.
