A system including an external apparatus and digital camera allows the external apparatus to set a set value which cannot be set by the stand-alone digital camera. In response to a request from the external apparatus (computer), the digital camera updates an image sensing set value table in which set values used for image sensing are recorded (S502). If this set value cannot be set by the stand-alone digital camera (“NO” in step S506), a message representing it is displayed on a display section (S508).