I use my Canon 5D Mark II with multiple YN-560 Mark IV flashes, triggered by a YN560-TX external flash control.
I tried to set up the external flash control but I failed. It says
flash is not compatible. Of course all flashes are powered on. I tried to shoot with high shutter speed (<= 1/1000s), but I can only shoot at 1/320 at the most.
What can I do to increase shutter speed?