I read this in the owners manual: The “Commander function” enables the SB-900 to trigger remote flash units without firing itself. To activate the “Commander function,” set the SB-900 as the master flash unit and set its flash mode to “Flash canceled." Does this mean that it basically does the same thing as the SU-800? The reason I bought the SU-800 is because of people blinking when they see the pre-flashes. Will the SB-900 command remotely via IR?