580 EX - CFn07 Question

[photodudeny1]

I recently added an external battery pack to use with my Canon 580 EX

Custom Function 07 determines whether the flash uses both internal and external power to recharge or just external.

Simplistically, I would think that both would be faster, but the manual says something along the lines of "if both are used and the internals become drained, shooting will be disabled."

Along that line of logic, does anyone know if using external only is going to be faster if the internal batteries are not as fresh as the external ones? And also, how the setting of the CFn 07 setting affects performance with the battery pack attached?

[klr.b]

using both internal batteries and an external pack to charge the flash's capacitor is indeed faster. the problem is that an external pack cannot power the flash; only the internal batteries can. so when the internal batteries die, your flash won't operate until you change out the internal batteries. because of this, i have the flash only use the external pack to recycle. i use a pixel battery pack and i lose a fraction of a second this way, which is not a big deal to me.

when using that CF while a external pack is plugged in, the internal batteries are only used to power the LCD and keep settings. i had some old batteries that were too weak to charge the cap in one of my flashes. i plugged the external pack in and it worked fine.

[tim]

If you tell it to use the power pack only it powers the flash electronics with internal cells, and the flash tube from the pack.

I let it use both sets of cells to charge the flash, because I wanted the best performance. I have spare batteries, but I rarely had to use them, even for all day weddings.

[css7493]

Theres a good and bad side here, I haven't put a lot of stock into having the unit recycle from the pack only, I use internal and external battery to reduce recycle time. On the other hand, I had the flash dying on me at a shoot a couple weeks ago (first time this has happened, theres likely another explanation) so I consider also sacrificing the recycle time to keep my flash alive . . . decisions . . .

[klr.b]

i agree the external battery packs can certainly last a day. the way i figure it, that half a second or so that i'm losing won't make a difference because i don't usually shoot that fast. if you do, then use both.

i'd just rather not be surprised. if the battery pack were to die, i could just remove it, and i know the batteries in the flash should last a while. once there's a break, i could change the batteries in the external pack. that way there's not really any down time.