high speed photography with sound trigger

[Whizzy4]

Hi everyone:

I'm wondering if you can help me. I'm interested in high speed photography using a sound trigger (glass breaking, balloons popping, etc.).

I purchased a sound trigger from a seller on Ebay. Wouldn't you know it - the sync cord will not work with my Canon 580EXII speedlight. The sync cord for the sound trigger is a 2.5 mm male/male cord. 2.5 mm male on both ends. That is what the seller indicated I would need. The speedlight sync cord looks to be unique to Canon. The person I purchased the sound trigger from said I could sync it (the sound trigger) to a pocketwizard, which in turn, would trigger the flash. My question for you is this: Has anyone had this type of issue? Do you have any thoughts or advice on how I would set this up?

I'd appreciate any advice you might have. Thanks.

 

[bratkinson]

If I remember my high school physics, sound travels at 770 mph, give or take. From the time the glass starts breaking (shot with a bullet, for example), the sound builds up to some level (small fractions of a second) before the sound trigger will actuate. Add to that the lag time (in nano-seconds, probably, but it's still a lag) from the electrical pulse until the flash gets to reasonably 'full brightness' and somewhere along the line your camera gets/got triggered (timed by what?) and you get your picture. By then, the bullet is long gone out of the frame, and the glass is already started dropping to the ground.

Is that what you're intending to capture?

Bottom line, I really don't see much use for a sound activated flash/camera unless it's used as some kind of burglar/intrusion "catch them in the act with a picture" installation. Or wild life in the woods at night, etc.

By the way...wouldn't the sound of the gunfire trigger the mechanism -before- the bullet got there?

Either way, I think it would be difficult to 'catch' the action 'as it occurs' in split second intervals given that the sound sensor will always trigger at the same moment in every exposure. Think pic 1: bullet 2" from glass, pic 2: bullet 1" from glass, pic 3: bullet nose contact with glass, pic 4: bullet past glass...etc

 

[ZapoTeX]

wouldn't the sound of the gunfire trigger the mechanism -before- the bullet got there?

This is probably what he's trying to achieve. You just need an adjustable time delay and after a few calculations and attempts you'll capture the bullet in the right place

For the sync cable: besides physical size and shape of the jack, make sure electrical specs are compatible. Don't know anything about Canon speedlights, but I hope specs are easy to find on Google.

Please post the results!