430ex....does not fire in the burst mode..

Not sure if it has something to do with the type of battery I am using. Is a rechargeable battery. I use the 430ex a lot for bird photography and under overcast sky or dense vegetations. I am shooting with a 1dmarkII. The flash often didn't fire on the third frame. Is it the unit not able to keep up with the shooting speed of the markII? Or the battery isn't powerful enough to sustain firing in the continuous mode???

The recycle time for the flash is 0.1 to 3.7 seconds depending on the battery. How may frames are you trying to take in a second?

Sounds like the flash is out of power by the 3rd shot. Shots 1 and 2 added up probably used more than the total charge the flash before it can recycle. Try increasing the ISO so the flash doesn't have to use as much power per shot (or a more powerful flash like the 580EX which would give you more reserve).

Thanks. That's what I thought.

blssdwlf wrote in post #5751164
Sounds like the flash is out of power by the 3rd shot. Shots 1 and 2 added up probably used more than the total charge the flash before it can recycle. Try increasing the ISO so the flash doesn't have to use as much power per shot (or a more powerful flash like the 580EX which would give you more reserve).

I set to 8.5 fps.

eddarr wrote in post #5749911
The recycle time for the flash is 0.1 to 3.7 seconds depending on the battery. How may frames are you trying to take in a second?

TooManyShots wrote in post #5755172
I set to 8.5 fps.

Unless you set the flash to a very, very low power, you will not find any consumer flash that can keep up with 8.5 fps.

Enjoy! Lon

FlashZebra wrote in post #5755258
Unless you set the flash to a very, very low power, you will not find any consumer flash that can keep up with 8.5 fps.

Enjoy! Lon

Is 1/8 considered very, very low power? Because I can run my 1D3 at 10 fps and my 580EX set to 1/8 power will easily keep up with it for a couple of seconds (and even longer if I weren't afraid of burning out my flash). Of course, you'd have to have an external battery pack attached to minimize the flash recycle time.

My 580EX will keep up with an 1D2 going full speed for about 5 frames at 1/8 power, if I use fresh NiMh batteries

I'd cal that very low power, not very, very low

PacAce wrote in post #5755401
Is 1/8 considered very, very low power? Because I can run my 1D3 at 10 fps and my 580EX set to 1/8 power will easily keep up with it for a couple of seconds (and even longer if I weren't afraid of burning out my flash). Of course, you'd have to have an external battery pack attached to minimize the flash recycle time.

Hey, don't push me into starting another "retarded mod" thread.

But, 1/8 power is EXACTLY between very low, and very very low. I just rounded to very, very low. But, it could have gone the other way and rounded to very low.

But to be more precise, this is what I should have written.

EXACT power (approximately) = (very low - 1/2 (very low) )

Enjoy! Lon

My 430ex keeps up in my 20d at 5fps. I have it set to ETTL, at 1/250th F2.8 and jpeg large.