Originally posted by dstructor HAHA, pretty helpful
That's it for HSS
HSS is a complicated system, it actual fires the flash multiple time during the photo, the reason is the shutter.
It kinda works like a window, at 1/180 the window is fully open across the frame so the whole sensor is lid by the flash light. With 1/360 the gap between the shutter is half the space so only half of the sensor is exposed at a time.
So when you flash then only half of the sensor is lid and you get a bar across the photo.
With HSS the number of flashes is calulated so that the flash actually fires the whole time during the exposure.