First of all, thanks to Dennis (aka Lichtwerk) for suggesting an easy and precise way to measure strobe recycling times (here). No, this level of precision really isn't necessary from a practical perspective but, it is so easy to achieve, it makes sense to adopt Dennis' suggested video-based approach as opposed to relying on a manualy operated stopwatch.
The technique is simply this: Record the flash firing/recycling then import the footage into a video editor and note on the timeline the moment the flash fires and the time when the ready light re-illuminates. The difference between these two data points will be the exact recycling time (exact within the constraints imposed by the 30fps frame rate).
For this exercise, I used the free AVS Video Editor software package. Recording was done with a Nikon D3100. I measured recycle times of the Einstein powered by a fully-charged VML at both 640Ws and at 320Ws (1 stop down). Multiple pops at each power were recorded.
The resulting frames as seen in the AVS editor looked like this:
My results were as follows:
640Ws
Pop 1: 3.920 seconds
Pop 2: 3.850 second
Pop 3: 3.798 Seconds
320Ws
Pop 1: 1.707 Seconds
Pop 2: 1.737 Seconds
Pop 3: 1.728 Seconds
For comparison purposes, I also did a quick test with an Elinchrom 600RX set to full power:
Pop 1: 3.731
Pop 2: 3.621
Pop 3: 3.591
So the VML is able to provide 3-1/2 to 4 second recycling time with a single 600-640Ws strobe. Reducing flash power shortens recycling times considerably.
Dave F.
