High Speed Flash Photography Triggers

lately i've been thinking more and more about getting back into my photography and have wanted to meddle with some high speed stuff.

ive done a few high speed photos of water droplets before that came out pretty good but it was just random timing either with bright spotlights and continuous drive or dumb luck with a dark room and the flash unit. i haven't even bothered trying broken glass or balloons with that technique

anyway i have a rebel XSi and a hot-shoe mounted speedflash i also have a couple mono lights I bought (but haven't used much since my body doesn't have the appropriate connector and i haven't purchased a wireless trigger unit)

what i don't have is a trigger setup and was wondering if anyone had some suggestions for purchasing or making either an IR or sound activated flash trigger and how i should set it up so i can use multiple light sources , optimally i would like to be able to use both my mono lights in the home and the speedflash (for portability if i want to rig up outside). ofc cost is a big issue and i don't want to spend huge amounts on the trigger.

I think the limiting factor here would be the flash duration, rather than the shutter speed. On a Speedlite, flash duration decreases as flash power decreases. That is, the longest flash duration is at full power. On a 580EX, I believe that flash duration is on the order of 1/13,000s at 1/64 power.

That is to say that even at a shutter speed of 1/250 (which you should be able to achieve with Pocketwizards or even Yongnuo RF-602s), if you can get the conditions right such that flash power is as low as it can be (and ambient light is minimized to avoid motion blur), you should be able to stop action quite effectively.

Most monolights do not use IGBT circuitry, and thus flash duration actually increases as power decreases. One notable exception is the Einstein from Paul C. Buff, which uses IGBT circuitry in 'Action" mode.

I haven't personally tested this, but I have read that when using Speedlites (and presumably any IGBT-based strobe), stopping action is actually easier with moderate shutter speeds (ie. 1/250) vs. going to high speed sync.

See here:

http://www.robgalbrait​h.com …age.asp?cid=7-10053-10715

edge100 wrote in post #11862423
I think the limiting factor here would be the flash duration, rather than the shutter speed. On a Speedlite, flash duration decreases as flash power decreases. That is, the longest flash duration is at full power. On a 580EX, I believe that flash duration is on the order of 1/13,000s at 1/64 power.

That is to say that even at a shutter speed of 1/250 (which you should be able to achieve with Pocketwizards or even Yongnuo RF-602s), if you can get the conditions right such that flash power is as low as it can be (and ambient light is minimized to avoid motion blur), you should be able to stop action quite effectively.

Most monolights do not use IGBT circuitry, and thus flash duration actually increases as power decreases. One notable exception is the Einstein from Paul C. Buff, which uses IGBT circuitry in 'Action" mode.

I haven't personally tested this, but I have read that when using Speedlites (and presumably any IGBT-based strobe), stopping action is actually easier with moderate shutter speeds (ie. 1/250) vs. going to high speed sync.

See here:

http://www.robgalbrait​h.com …age.asp?cid=7-10053-10715

i'm not too concerned with flash duration. both the speedlight and monolight should be at least above 1/5000 certainly plenty for water/milk droplets i might look into other flashes if it poses a problem later if i try shooting BBs or somethign. for now all i'm really concerned with is the flash trigger.

SpinningCone wrote in post #11862696
i'm not too concerned with flash duration. both the speedlight and monolight should be at least above 1/5000 certainly plenty for water/milk droplets i might look into other flashes if it poses a problem later if i try shooting BBs or somethign. for now all i'm really concerned with is the flash trigger.

Not many monolights have flash durations of 1/5000. AB1600s are t.5 = 1/1800 at full power. Elinchrom 600RXs are t.5 = 1/2000 at full power. Things get worse from there. http://www.robgalbrait​h.com …age.asp?cid=7-10053-10715

What I'm saying is that any wireless trigger will work if you can get flash duration short enough. Or maybe I'm totally missing your point.

edge100 wrote in post #11862830
Not many monolights have flash durations of 1/5000. AB1600s are t.5 = 1/1800 at full power. Elinchrom 600RXs are t.5 = 1/2000 at full power. Things get worse from there. http://www.robgalbrait​h.com …age.asp?cid=7-10053-10715

What I'm saying is that any wireless trigger will work if you can get flash duration short enough. Or maybe I'm totally missing your point.

hmm didn't know they were that bad. guess ill have to stick to the speedflash or at least fool with the mono lights to see which subjects are within range of my lights duration.

what i need is a sound trigger to detect the balloon popping or an ir/laser trigger to detect the drop passing , delay controls are desirable so i can dial in the event.

SpinningCone wrote in post #11862879
hmm didn't know they were that bad. guess ill have to stick to the speedflash or at least fool with the mono lights to see which subjects are within range of my lights duration.

what i need is a sound trigger to detect the balloon popping or an ir/laser trigger to detect the drop passing , delay controls are desirable so i can dial in the event.

Ahh. I see. Well, I can't help you with the trigger. But do be aware re: flash durations for stopping motion.

edge100 wrote in post #11862830
Not many monolights have flash durations of 1/5000. AB1600s are t.5 = 1/1800 at full power. Elinchrom 600RXs are t.5 = 1/2000 at full power. Things get worse from there. http://www.robgalbrait​h.com …age.asp?cid=7-10053-10715

What I'm saying is that any wireless trigger will work if you can get flash duration short enough. Or maybe I'm totally missing your point.

You're looking at the wrong flash duration. 1/1800 @ full power for the AB1600 is the t.5 flash duration (which doesn't really matter). That one that matters for stopping action is the t.1 duration which is only 1/600 @ full power and 1/300 @ 1/64th power. Other than that, you were on the right track

Here's a better explanation of why, quoted from Paul C. Buff's website:

The standard engineering term for stating flash duration is “t.5”. This describes the time it takes for 50% of the total flashpower to be dissipated. Whenever the simple designation “Flash Duration” is specified it can be assumed to be the t.5 spec.

However, the t.5 spec doesn’t adequately predict the actual motion freezing capability of a flash. There is a much longer trailing edge that continues to emit the remaining 50% of the light. This causes considerably more motion blur than the t.5 spec implies. In order to better compare flash duration specs to an equivalent shutter speed, the term “t.1” was introduced by the photo industry. t.1 specifies the time it takes for 90% of the total flash to be emitted. But even following the t.1 time there is still light being emitted at sufficient intensity to cause some ghosting or motion trails.

As for the 1/5000th flash duration, I don't know where you got that # but good luck trying to find a monolight with that sort of duration unless you plan on going with the Einstein or other alternatives such as the Elinchrom Free Lite A which will burn a major hole in your wallet. If it's HSS you want in your triggers, the only budget alternative I`ve seen to the pocket wizards are these: Pixel Knight TR-332's. If I misunderstood and you don`t care about HSS, I`d honestly just wait till the end of February when YongNuo releases the RF-603`s. You really can`t go wrong. They are so inexpensive that if they happen to break, who cares... buy another set!

Inexpensive
http://www.hiviz.com/k​its/products.htm

A little more
http://www.cognisys-inc.com/home_cogn.php

monty28428 wrote in post #11862940
http://www.hiviz.com/k​its/products.htm

Thank you! exactly what i'm looking for and pretty good pricing for a do it yourself circuit.

as for flash duration my speedflash should work for what i need. i didn't realize that the moonlights would be so slow by comparison. perhaps if i get a new body or figure out how to get the mono lights to work with high speed sync i can bring the duration to 1/4000

found a better article about flash duration here for anyone else who's interested http://www.scantips.co​m/speed.html

SpinningCone wrote in post #11863004
Thank you! exactly what i'm looking for and pretty good pricing for a do it yourself circuit.

as for flash duration my speedflash should work for what i need. i didn't realize that the moonlights would be so slow by comparison. perhaps if i get a new body or figure out how to get the mono lights to work with high speed sync i can bring the duration to 1/4000

found a better article about flash duration here for anyone else who's interested http://www.scantips.co​m/speed.html

HSS has nothing to do with your camera body. It has everything to do with the triggers you`re using. Most budget triggers do not include HSS which is why I linked the Pixel Knights because I don`t know of any other triggers that include HSS for such a reasonable price. Pocket wizards and Radio poppers can cost as much as $200+ per unit, heh.

Aressem wrote in post #11863046
HSS has nothing to do with your camera body. It has everything to do with the triggers you`re using. Most budget triggers do not include HSS which is why I linked the Pixel Knights because I don`t know of any other triggers that include HSS for such a reasonable price. Pocket wizards and Radio poppers can cost as much as $200+ per unit, heh.

this is true. the cheap wireless triggers i have on my wishlist will only do bout 1/200 but if i end up springing for the 7D it will have a PC Sync connector which (unless i'm missing something) should allow HSS. I found a few hotshoe adapters that add a pc-sync port but i'm not sure if they would allow HSS

it's probably moot anyway. likely i will get the 60D or t3i instead of the 7D due to cost.

monty28428 wrote in post #11862940
Inexpensive
http://www.hiviz.com/k​its/products.htm

A little more
http://www.cognisys-inc.com/home_cogn.php

I've been looking into High Speed Photography kits and ended up in the hiviz site. I think I'm going to order the Multi-Trigger Kit and assemble it myself (or at least I'm confident I can do it)

I think it's enough to start, it can be triggered by sound or photogate and has the delay circuit to tune the right moment. I still need to figure out a way to connect it to my camera or flash. They sell the adaptors for the flash, but they are too expensive compared with the kit or ebay prices. For the camera I think I'm gonna order a cheap ebay remote and cut the cable.