580ex only firing on full power every third shot

[John Mac]

I had serious problems with one of my 580 ex's last saturday at a wedding where by it was only firing on full power every second/third shot. It would fire at a low power that would not shine any light at all. Still have the same problem with it, anyone encounter this problem before?

Thanks in advance

5d, 40d & 20d
580ex x 2
24-105L
70-200L
17-40L
Tamron 28-75
Bowens 500 studio kit

[PacAce]

Sounds like a battery problem. Have you tried charging up your batteries or putting in a new set?

[John Mac]

Yes, I changed batteries (Was using the cpe4 battery pack also) no difference.

[roli_bark]

Not sure, but It looks like a recharging capacitor [inside the 580EX] problem.

[René Damkot]

Are you talking maximum frame rate? The flash does need *some* time to recharge...

Then again: IMHO if you need full power flash, you're not doing something right.
Use higher ISO / faster lenses.