hey guys.. i've got a question. Occasionally, when using my 580exII's as remote flashes, I've noticed that at the end of the night, they've switched over to M mode and the power is set to 1/128th... I have a feeling that they are doing this because the batteries have gotten low and it is the flashes way of preserving the little remaining battery power... but I can't seem to find this anywhere in the manual.
I haven't, but why don't you run a test. 1 with whatever batteries you normally use and 1 with a battery pack. I've never had the flash switch modes or power levels, but maybe I don't get the batteries low enough.
Richard, what are you using to trigger the OCF? Canon's built in IR system and Pocket Wizards both work with the flash in ETTL(II) mode, so I assume you're starting that way. When the units switch to M mode, do they then quit firing?
It's possible that you've run the batteries so low that they're not even maintaining settings, but I would think before that point they wouldn't have enough juice to fire.
I am using Radio Popper PX system, which essentially transfers Canon's IR signal to radio and trasmits it that way.
When it switches to M mode.. it continues to fire. The way I shoot, it doesn't actually change much in terms of output... I'm just trying to figure out why its happening.
They shouldn't switch over to M unless you have told them to from the Master Flash. I've run my batteries down very low and never had them switch modes, they just take forever to recycle, until they just don't recycle at all.
Maybe the slaves aren't getting the full signal from the RP's and they are changing modes.
Have you tried without using the RP and just using the canon master/slave function. .?
As I understand it the RP works by taking the electro pulses from the flash head as the flash pulses quickly and transmits them via radio waves to be picked up and changed back at the slave.
There is probably a chance that the code is getting garbled somewhere in the chain.
