Canon 580Ex Flash Duration
I was curious as to what I could freeze using my Canon 580Ex flashgun so I had a play in the lab using a photodiode and scope to measure the flash duration of the flashgun (averaged value over 4 flashes) at the various power output settings. The results were:
1/1 power = 1/1000 second
1/2 power = 1/2000
1/4 power = 1/4000
1/8 power = 1/9000
1/16 power = 1/15000
1/32 power = 1/21000
1/64 power = 1/30000
1/128 power = 1/35000
“What does this mean” I hear you scream, closely followed by “wtf has this to do with photography”?
Well the answer is, in order to freeze the movement of a fast moving subject a photographer will, at first, try to freeze the movement using a fast shutter speed. The maximum shutter speed on a good DSLR is around 1/8000 second but in order to use this speed you either need:
very, very strong lighting,
a wide open aperture and/or
a high ISO setting
An alternative is to use a flashgun(s) and by reducing the power output of the flashgun the flash durations can be as short as 1/35000 second for the 580Ex flashgun. If the flash is placed very close to the subject a small aperture and low ISO setting can also be used.
Various experiments with High Speed Flash can be viewed here
Tags: Canon 580Ex Flashgun, Flash duration, Flash Experiments, High Speed Photography
August 3rd, 2008 at 8:57 am
Morning Kev,
I have spent eons trying to produce a single, decent ‘high speed’ shot. All of which, are c**p. Having just read your ditty above, the penny has finally dropped. Of course, it all makes perfect sense to me now. So, huge thanks. (Pity my 580EX didn’t come with a decent instruction manual in the first place and I didn’t come upon your website sooner!)
Happy snappin’
Tutty bye
Kym
August 3rd, 2008 at 4:46 pm
glad to be of help Kym, just shout if I can help you in any way