I have set the camera on HighSpeedSync by going to flash setting in camera and setting the speed to 1/350 sec. ( on
Then I researched a little and looks like there is not a setting for Nikon Flashes -
SB 910 in my case - to put them in High Speed Sync and we just set it in camera which I did above.
Then I put the PocketWizard Plus III on
HSR mode which their manual says it is for high speed sync mode.
But when I shot at
1/400sec, I got that black curtain thing in the image.