I would like to update/clarify this question. I do understand sync speed and FP mode on our speedlights. What my original inquiry was about was why is there the two settings of 1/250 and 1/250*FP mode? As I ponder this and read the replies here- I wonder if 1/250*FP mode instructs the flash to start the flash strobing. If so, then I would be curious as to why? If it syncs at 1/250 why is high speed sync needed at this setting?