580EX ll fires blanks

[jmaphotography]

<p>Shooting a corporate event last night in a large night club with my 1DS 3 and a 580EX ll, plus a Canon battery pack, both with Eneloop rechargeable batteries, I found after about 2hours shooting, probably 300 shoots, that the 580EX ll was not always flashing. In other words, an almost black image. It seemed that the unit wasn't recycling quickly enough - I noticed the red indicator light was ocassionally still charging from green to red. Then it would flash. Embarrassing moments when the CEO and his guests are in front of your camera. <br>

Since I have the 580EX ll attatched to the Canon battery pack, I thought this should not occur. After disconnecting the pack from the speedlite and reconnecting, it appeared to function more as it should.<br>

Can someone through any light (sorry) on the situation? Thanks<br>

John</p>

 

[alec_myers]

<p>The 580EXII has various (irritating) internal protections to prevent overheating of the flash head - could it be thermal protection cutting in? 300 shots in two hours shouldn't be enough to overheat but if 50 of those shots were at full power and all in the last few minutes then it might. </p>

[elliot1]

<p>Did you try changing the batteries with a fresh set during the event? Assuming your flash is not malfunctioning weak batteries would likely be the cause of your troubles.</p>

[roger_barnett]

<p>Sorry to hear about the blank firing....It din't get a vasectomy when you weren't looking, did it....?</p>

<p>Uhoh....sorry, lol</p>

[jmaphotography]

<p>Thanks for responses. I think most of the shooting was at a regular pace, though occasionally I'd fire a couple/three off, but not enough, I wouldn't have thought to cause any overheating etc. This has happened before and it seems to be at around 300 shots or so. I'll try and refresh next time with a new set of batteries for the flash and see if it's just the flash batteries draining.<br>

But that doesn't explain, then, why my Canon battery pack isn't 'taking up the slack..' Isn't the purpose of the pack to supplement the flashgun batteries, so that the whole system lasts longer, with faster recycling times? Thanks for your suggestions.</p>

[picturesque]

<p>I've had this happen at weddings. It is indeed the thermal switch OR your batteries are nearing the point at which the flash will not 'accept' their input. Weird, but true. If you read the flash instruction book, you will see (I believe it is page 7) that the recycling time will be extended when the overheating switch is engaged. If, for instance, you fired off near full power (bouncing flash) flashes, not necessarily in a row, but at a steady clip, the switch would engage.</p>

<p>When my flash has experienced problems due to battery depletion (I also use Eneloops), it will turn on briefly and fire once, then turn off completely--won't turn on. This happens rather suddenly with Eneloops--there is no period of gradual 'decay'.</p>

<p>Sometimes, you can continue, in either case, by inserting cool, freshly charged AAs.</p>

<p>As for the pack, if you have the custom function on the flash set to use both the AAs and pack, the pack will not help recycle the flash at all if the AAs are depleted or near depleted, even if the pack isn't. I have my flash set to use the pack only, although you still need the AAs to run the flash. I only use the pack for certain times during a wedding. And if the overheating switch is engaged, the pack won't help either.</p>

<p>I keep a 580EX original close by in case I can't get the 580EX II working. Ironic but true.</p>

[andrew robertson]

<p>Why not test to see if you can recreate the behavior, then you will know what to avoid?</p>

[jmaphotography]

<p>Yes, you are right. I will make a special effort to bear in mind 1. how quickly I'm shooting, 2. at what number of shots the problem arises, and 3. replace the flash batteries with a fresh pack to see if that solves the issue. That should tell me at least if it's actually just the flash batteries powering down.<br>

The flash Cfn 12 is set to 0, whereby both flash and the CP-E4 battery pack are power sources together. I'll also have to note whether the battery pack connection is constantly firmly attached to the flash, as I do tend to pull/stretch about.<br>

I'm out to another corporate event tonight, so we'll see.</p>