Originally posted by awaldram Given most flashes at full power deliver t1 figures in the 1/125 region then having a faster sync speed to kill sun is more myth than reality.
While I agree that at full power you're losing some of your light to the shutter curtains, ideally a higher sync speed would allow you to use a lower power setting on your flash and still get the same result. Flash durations decrease dramatically as the output drops.
Read up on the Nikon D70s, it's popular among Strobists because it features a hybrid shutter, part mechanical and part electronic. The way it works is the first curtain slides open, some time passes, the sensor begins recording, the flash fires, the sensor finishes recording, and the shutter slides closed. It's like a leaf shutter in that the sensor is always exposed even at its highest shutter speed.
So think about it, even at f/2, under sunny 16 conditions, you'd be able to shoot at 1/8000th of a second, at 1/32nd power, capture the entire flash, and still have a GN of about 7.5m (24ft). You could even freeze a hummingbird's wings at that speed. Recycle times would be nonexistent, and you would get more shots per battery. Lots of great things happen when you shoot at less than full power.