An image pickup apparatus includes a capturing unit configured to capture a subject; a generating unit configured to generate a request packet to request information of an image stored in an external apparatus, wherein the request packet includes a parameter of the capturing; a request packet transmitting unit configured to transmit the request packet to the external apparatus, a response packet receiving unit configured to receive a response packet corresponding to the request packet, wherein the response packet includes the information of the image stored in the external apparatus; and an image acquiring unit configured to acquire the image from the external apparatus based on the information included in the response packet, wherein the generating unit generates the request packet in response to instructions to allow the capturing unit to perform capturing.