Quote Originally Posted by sbattert View Post
I think the duration of the old flashes were much longer, so it didn't matter as much. You didn't have to synchronize the shutter being open all the way with the burst of flash. The flash lasted much longer than the shutter speed.
At lower power level modern flashes can have very short duration but at full power I think the trend is to make the duration longer rather than shorter. Typical full power flash duration of the 70's is around 1/1000 while new flashes is around 1/300 or so. I think that's because old flashes used higher voltage and less capacitance while new flashes use lower voltage and higher capacitance.