NEED HELP! - can't freeze action with strobe

I can't seem to freeze action (children jumping on a trampoline) with photogenic PL1250 strobe in a softbox. There is no ambient light. Camera on tripod at max 1/200 shutter sync speed. ISO 100. Tried f/11 all the way to f/22. I still get a slight blur. I understand that I might need a different strobe with shorter flash duration, but would like to hear your ideas or feedback. see attached photo for more info. I am using a white seamless paper for background that is lit with 2 strobes with reflective silver umbrellas. Thanks.

What pics??

Yes, you are correct.....
You'll need a flash system that has a faster flash duration.

roumin wrote in post #15317928
I can't seem to freeze action (children jumping on a trampoline) with photogenic PL1250 strobe in a softbox. There is no ambient light. Camera on tripod at max 1/200 shutter sync speed. ISO 100. Tried f/11 all the way to f/22. I still get a slight blur. I understand that I might need a different strobe with shorter flash duration, but would like to hear your ideas or feedback. see attached photo for more info. I am using a white seamless paper for background that is lit with 2 strobes with reflective silver umbrellas. Thanks.

Try again. We don't see any images.

Flash duration for the photogenic PL1250 says 1/1300" at full power, so that should be sufficient for a child on a trampoline, unless there is really rapid motion in the hands.

If there was no ambient, then the blur shouldn't be from ghosting.

Was the strobe at max power? Duration on strobes typically gets slower at lower power (except IGBT strobes like speedlites or Einstein)... 1/640 second at 1/32 power.

sorry - had to downsize the images. they're uploaded now. strobes were firing at mid power setting

Flash duration gets LONGER as the power is reduced. Also, remember that the specs generally are for t.5 and with the shutter open for 1/200 second, the flash illumination will include all the exposure so the t.1 speed is also a factor.

If you want to stop action you have to use monolights or speedlites with flash duration approaching 1/4000. Generally photographers wanting to stop action use Speedlites at less than full power since the flash duration diminishes as power is reduced. As mentioned, the only monolight with similar capabilities is the Buff Einstein. There is an article on this website that describes how it works; http://www.robgalbrait​h.com …age.asp?cid=7-10053-10715

http://www.youtube.com​/watch?v=TSwguTuYfhE
http://www.youtube.com​/watch?v=1TvwUz9EcuE

The first one seems more of a focus issue, where as the second looks better but feet are still blurry. I think your setup has something to do with this.

Is there a reason as to why you are having them jump on a trampoline instead of saying "1...2...3...JUMP" then take the picture? that way the feet wont be moving quite so fast and your focus will be more accurate because they are jumping in place.

So, if my flash duration is 1/800-1/1500,that applies shooting at 1/200 only?

whoty wrote in post #15318868
So, if my flash duration is 1/800-1/1500,that applies shooting at 1/200 only?

if your t.5 or t.1 (measurement of flash duration) is 1/800-1/1500 that applies at full power of your strobe. So if you have a 300w/s strobe then firing it at 300 w/s will give you the fastest flash duration.

Brendo666 wrote in post #15318926
if your t.5 or t.1 (measurement of flash duration) is 1/800-1/1500 that applies at full power of your strobe. So if you have a 300w/s strobe then firing it at 300 w/s will give you the fastest flash duration.

Ok,gotcha. I'm still in the learning stages of flash work. Got 8 months under my belt so far.

whoty wrote in post #15318868
So, if my flash duration is 1/800-1/1500,that applies shooting at 1/200 only?

Shutter speed will only effect the ambient in the studio. Flash duration is the pulse of the flash and with no ambient light if it is fast enough will completely freeze movement.

This studio shot was with a Canon Mark II, F11, 1/125 sec, ISO 200.
Flash was a Profoto Compact 600 R with only has a flash duration of (t 0.5) 1/850 sec @ maximum power

Crank the strobe up to full power, adjust aperture accordingly, and give it another try.

Try to catch them at the top of the bounce.

They won't all be keepers but you'll get some good ones. This was done with a couple Alienbees B1600 units at full power.

^^^ As Curtis and Jerry suggest.
Remember that the shortest flash duration is at full power for most monolights.
If full power is too much light, then use a polarizing gell, or multiple diffusion panels to cut the light getting to the subject.

Even Joe McNally has to do multiple takes to get the action stopped just the way he wants it. (One of his tutorials on Kelby Training site addresses similar subject and how he got the shot.)