I have a 430EX mounted on the hotshoe of a Canon 40D. I would like to use this in the studio and have the flash fire every time I shoot a photo. However it only fires sometimes. I am using manual (M) mode. The flash has exhibited this behavior from day one and I rarely use it because of this, now it is two years old.

When I shoot outdoors, the flash always fires if there is "not enough light". However I am not able to make it flash compulsorily.

Things I have tried that didn't produce results:

  • Camera's "pop up flash button"
  • "Manual mode" on Speedlite
  • Reading the entire Speedlite manual front to back
  • Reduce shooting speed to less than one per second
  • Using program (P) mode

I am embarrassed to use this during a studio shoot because it will not work reliably and I don't know how to fix it. This shows the model I don't know what I'm doing and I need to regain their trust.

  • \$\begingroup\$ What settings do you use exactly (camera and flash), what is the exposure meter reading and what frame rate do you use? \$\endgroup\$
    – null
    Commented May 17, 2015 at 18:21
  • 1
    \$\begingroup\$ Would need to know the settings and also how long between exposures; is it because the flash recycle time is slower than the interval between shots? \$\endgroup\$ Commented May 17, 2015 at 22:32
  • \$\begingroup\$ Sounds like a battery issue. \$\endgroup\$
    – dpollitt
    Commented May 18, 2015 at 4:03
  • 1
    \$\begingroup\$ Are you waiting until the PILOT lights up red before shooting? \$\endgroup\$
    – inkista
    Commented May 18, 2015 at 20:51
  • \$\begingroup\$ Using camera on M mode with various ISO/fstop/shutter settings. The flash is on M mode with 1/1 showing. \$\endgroup\$ Commented May 19, 2015 at 13:46

1 Answer 1


Given that everything's on manual, that you're firing the flash at full power (1/1), and that you think waiting one second between shots is sufficient, I'm going to take an educated guess and say that your problem is that you're not waiting for the flash to fully recycle before you take a shot and/or you've got the power level on the flash set too high. It could also be that your batteries are not in good health or are not fully charged.

Adjust your expectations on how long it takes a flash to cycle: the recycle time for a full-power burst in the 430EX's specs is 3.7 seconds with alkalines, 2 seconds with NiMh rechargeables. Your flash is run on little AA batteries. These don't prove a huge amount of juice. Your flash uses a capacitor to store charge that it draws from the batteries over time, and then when you fire the flash, all that charge is released at once. But drawing a full-power burst's amount of charge takes time. This is why I asked if you're waiting until the PILOT button lights up red before you take the shot. While it's recharging the capacitor, the flash's PILOT button will be green. It will light up red when the capacitor is full and the flash is ready to fire again.

You can reduce the power requirements for a recycle by reducing the power setting on the flash. If you were down at 1/16 power, chances are good you could easily pop off shots at 1 second intervals without too much of an issue--although you might run the risk of overheating the flash if you do it too many times in a row too quickly. Never use burst mode when shooting flash in a studio unless you know you can use a very low level of flash.

  • \$\begingroup\$ Thank you, this makes great sense. I am reducing to smaller power and get consistent and great results now. \$\endgroup\$ Commented May 21, 2015 at 20:36
  • \$\begingroup\$ Also, a note for others: When first using the light I now wait a full minute or two before using. This significantly reduces the recycle time. \$\endgroup\$ Commented Oct 15, 2015 at 13:53

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