Originally posted by bdery It's actually a mix of both. The limitation is dictated by the shortest time that will allow the sensor to be exposed, without being partially blocked by part of the shutter. In this view it's a camera limitation.
However, if the flash was able to shoot light for the whole exposure time, it would not matter if the sensor was partially obscured or not. so it's also a flash limitation.
No, it's completely a camera limitation.
Cameras with leaf shutters can sync at any speed because there is no focal plane shutter to deal with.
HSS is a workaround to get flash to work at higher shutter speeds with focal plane shutters.
My earlier point though, was that the camera will not trigger the flash above 1/180, even if you are willing to live with the shadow.