Answer: watchthebirdie

AnswerCrossword Clue
WATCHTHEBIRDIEPhotographer's command
WATCHTHEBIRDIEShutterbug's suggestion
WATCHTHEBIRDIEPhotographer's instruction
WATCHTHEBIRDIEWhat you might hear before being shot
WATCHTHEBIRDIEPredecessor of "Say cheese!"
WATCHTHEBIRDIEPhotographer's request