When talking about strobes we usually go for power, one of the first things we ask is what is the GN on the little guy, or how many WS on the big bro. That is usually the questions when you want to light more.
But what if you want to light fast? what if you are trying to freeze the action. A water drop crown or a popping balloon a good example of something slow that you want to freeze, and a bullet will be an example of something fast that you want to stop in mid air.
Strobist has a great theoretical discussion about two relevant time indicators: T0.5 and T1.0. In a nutshell, T.5 is the time it takes your flash to output half of the light, and T1.0 is the time it takes your flash to output 90% of the light.
The lower the power is, the faster the pop should be.
While Nikon strobes have this (partial) info on their specs, Canon strobes specs (at least the ones I found) lack this info all together. Wouldn’t it be interesting to see how strobes measure up to those numbers in real life?
That is exactly what Maurice Ribble (from tech photo blog and cameraaxe) thought. So he made a video explaining how to measure that duration with an oscilloscope (warning, geeky equipment required) and tested a Yongnuo 460 against a Canon 580EX II and surprisingly the YN was faster. (there are some doubts raised in an interesting Strobist thread if you are engineering inclined). Video after the jump.
Measuring Flash Duration on tech photo blog