The 430EX can shoot 43 meters at the longest zoom position when shooting at f/1 and ISO 100 (Canon flash models are their guide number expressed in decimeters - who ever thinks in decimeters?). f/8 is six stops less light, or 1/64th as much light. So...it'll have enough power to reach about 2 feet, 2 inches at max power. Boosting to ISO 400 would get you out to 8 feet, 8 inches, or would let you run at 1/4 power, most likely cutting your recycle time to 3/4 second or so. I don't know the 430s well, so if they have a green flash confirmation light, were you even getting that?


The 580EX II would have more power, likely allowing you to pop away at a lower relative power (maybe 7/8s of full power at ISO 100), thereby shaving some recycle time. Adding the external battery pack (of which I'm now a HUGE fan!) would drop it to roughly 1 second.


The other shooter's settings could have resulted in shots that needed significantly less power - wider aperture, higher ISO, different metering, who knows. It might have been a good time to swap flashes and try.