Using Flash To Get Stop Action

Posted on: October 25th, 2013 0

Stopping Birds

I made this video to demonstrate the stopping power of speedlights. I used 3 speedlights so I wouldn’t need to use any one at full power. The flash duration is slowest at full power. I used speedlights by 3 different companies; Canon, LumoPro, and Yongnuo. There fall-off times varied slightly, but at 1/4 power on each, the duration for all 3 was slightly faster than 1/2000th. That’s fast enough to stop most movement, but the tiny birds visiting my bird feeder were unbelievably quick. I can’t say I got super-sharp freeze-frame, but I did get pretty darn close. Watch the video to see how I did it.

Varying Fall-Off Times

I noticed upon zooming in to some of the better stop-action shots, that there was an interesting anomally….there were 2 ghosted edges along with the solid image of the bird in flight.

click for larger image

click for larger image

It looks like bizarre camera shake. I did shoot hand-held at 1/200th with a Canon 70-200 f/4 IS lens. If it was camera shake, we wouldn’t see 3 distinct edges. Plus, the exposure was set so there was almost no ambient light in the shot.

The most logical explanation is that the 3 flashes had sightly different fall-off times. Since the light didn’t end at exactly the same time for all 3, those bizarre edges were probably the result of lingering light for the slightly….ever so slightly…..slower flash durations. The only other interesting thing is that even 1/2000th wasn’t fast enough to stop those wings! At any rate, here’s the video:

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