EOS-1D X Mark III
- Jan 29, 2011
Yes and the official specification is incorrect as per my link. Flashes don’t flash that fast.That's from the official specification, though.
Besides, you don't need full power output for fill flash if you don't need HSS. You have GN12.5 (in meters) for the 80mm flash zoom at 1/16 of full power, which means you have pretty decent burst capability. With HSS at 1/1000, you will get the same GN for just a single full-power shot.
Again I was not asking about the utility of speedlites, which I use to their maximum effect when needed, I was asking what use is a 1/2000 sync speed to people “shooting portraits with strobes”