Spent the day photographing hummers in my backyard. The setup was simple - a feeder in the shade hanging from the roof of my back porch, a couple of off-camera radio controlled speedlights set up about three feet from the feeder @ 1/128th power, my Canon EOS 1D MKIIN on a tripod with a 70-200mm @ 200mm, manual exposure set to the max sync speed of the radio strobes (1/320th of a second) with the background 2 stops under exposed - and bang!
Not so fast. According to others on the web, my 580EX flash at this power setting is suppose to produce a 1/30,000th of a second duration flash - enough to completely freeze any motion of these little criters - or so you would think. Someone is lying. Either these birds are DAMN fast or the flash isn't. Me thinks its the later.