A method of synchronizing a remote device to image acquisition by a camera body including detecting a voltage change of the camera body that occurs prior to shutter opening. The detected voltage change is used to determine a time to synchronize the remote device to image acquisition via wireless communication. For example, the detected voltage change may be used to predict when the shutter of the camera will be open. A wireless communication system for synchronizing a remote device to a camera body may include a memory having information used to synchronize the remote device to image acquisition based on the detection of the change in voltage occurring prior to a shutter opening.