{TAIL ~ a focus detection unit} configured to performing {HEAD ~ focus detection} on the basis of the phase difference detection signal 
{ TAIL ~ a focus detection unit } configured to performing { HEAD ~ focus detection } on the basis of the phase difference detection signal
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH