I would like to photograph a falling object in burst mode and light it using an off camera flash.

My current gear includes the following:

  • Canon 550D
  • Starblitz 2000BTZ flash
  • Two Cactus V5 wireless transceivers
  • I can borrow a second Starblitz flash

Currently the Startblitz can't keep up with the burst speed of my camera (3.7fps). I figured I would need to have a second flash (with an additional wireless transceiver) that fires on the second frame, while the first flash recharges, then on the third frame the first flash fires again, the second one recharges, etc...

How can I direct all the odd trigger signals to the first flash and all the even trigger signals to the second flash? Is that even possible with my current gear? Or is there a whole different approach to shooting with burst mode using a flash?


2 Answers 2


When you take a picture with a flash, the flash discharges from a bank of capacitors for a given time to regulate the flash power. The higher power the flash, the longer the flash is discharged for, and thus, the more power is used and the longer recharge takes.

The most common solution for your problem is to alter the criteria so that you can take more flashes in a given time. This can be accomplished in one of three ways. The easiest way is to simply reduce flash power. If the flash is active for less time, there is less power that needs to be replenished and the flash will be ready sooner. For example, while the flash I use generally requires a couple seconds between full power flashes, at 1/128 power, it can make 40 flashes in under 1/50th of a second.

If you need a given power level the answer to this problem is either a flash that takes an external charge pack or a flash with better capacitors or more power internally. When I'm using my Canon 600EX-RT, it is limited to about one full power flash per couple seconds, with an external battery pack, that extra power boosts it to less than 1 second per full power recharge (much faster if using lower power). Similarly, since the power of the flash is higher than cheaper flashes, it doesn't have to discharge as much (percentage wise) to get a particular flash, so it recovers faster.

While your idea for alternating flashes is interesting, I'm not aware of any systems that allow for that, at-least not for under the cost of simply buying a flash that would support a relatively moderate speed of 4 flashes per second.

  • 2
    \$\begingroup\$ Well, there is a commercially-available alternating system, but yer average low-rent hobbyist isn't going to like it: Broncolor's high-end units can be set to use up to four packs (although it's practically limited to two packs if you need identical lighting, since that's the max you can run to a single dual-tube head). That'll let you use the Scoro 3200S packs at half-power or the 1600 at full power for 4 fps (which is a LOT of light). And you can co-opt Hensel's Freemask option to do a doubling as well. More speedlights at lower power is much cheaper. \$\endgroup\$
    – user2719
    Jan 1, 2014 at 2:52

While it's certainly overkill for the original problem I found a device that can trigger different groups of flashes quickly after each other.

According to this article the Pocket Wizard Plus III and MultiMax have a feature called Speed Cycler. This function allows to trigger different (groups of) flashes in rapid succession.

  • \$\begingroup\$ +1 for remembering you asked the question way back to post an answer when you found it. \$\endgroup\$
    – AJ Henderson
    Jul 17, 2014 at 20:53

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