6D conflict with 580ex II....?

For some reason, when I put my 580ex II on my 6D I am having conflicts I don't have with my other cameras. If I try to fire frames at a faster rate, the flash misfires on about 1 out of every 3 or 4 frames. However, if I take it off my 6D and put it on my 1Ds2, 1D2, or 50D, I don't have this issue, it just fires no problem. I can pretty much hold the shutter release button down and with all my cameras, other than the 6D, the flash will pretty much keep up with every frame AND with the same out put power. I have also noticed that I can take 2 or 3 shots pretty close together in the exact same setting and the flash output when on the 6D varies A LOT.

Any ideas?

If it was happening to all my cameras I would know it's the flash, but it's only the 6D. I also notice that the green light comes on and stays on longer after flash output than it does on any of my other cameras. I'm sure its one of the settings but I can't figure it out and it's driving me nuts.

Thanks in advance for any help you can offer.

Sounds like a contact issue. Try cleaning the flash and camera contacts.

losangelino wrote in post #15932443
Sounds like a contact issue. Try cleaning the flash and camera contacts.

First thing I did was clean the contacts.

As I look at the flash I am noticing that it has something to do with the green light. When the green light is on, the flash output is lowered. The green light, for some reason, stays on longer after a shot on my 6D than it does on my 1Ds2. I keep switching it back and forth and there is a noticeable difference. From what the manual states, the green light is for flash exposure confirmation. Why would that affect flash output?

Also, I can clearly see the flash symbol in my view finder but the flash still doesn't fire, or not at the correct output. It recycles very quickly and I can see the flash symbol, but I just can't figure out the extreme variance in output light.

Interesting. I've been having some flash output issues with my 6D but attributed it to a bad Ettl cable and presumably incompatible flash triggers. Maybe there is more to it....

I also noticed an odd phenomena when I was having flash issues. If my flash didn't fire properly (or if I had it powered off, the shutter speed would drop considerably - I was shooting in MANUAL!

Is there a particular brand of contact cleaner you guys prefer?

TGrundvig wrote in post #15932562
As I look at the flash I am noticing that it has something to do with the green light. When the green light is on, the flash output is lowered. The green light, for some reason, stays on longer after a shot on my 6D than it does on my 1Ds2. I keep switching it back and forth and there is a noticeable difference. From what the manual states, the green light is for flash exposure confirmation. Why would that affect flash output?

When switched on, the pilot should move quickly from green to red. When it is red, the flash is ready.

Replace or recondition/recharge your batteries!

Are you using the exact same settings on the 6D as the other cameras? That would make a difference. For instance, if the settings on the 6D has the flash firing at a higher power than the 1Ds2, then the flash can't recycle as fast as when it's on the 1Ds2 (more power = longer recycle).

As Clive pointed out, a red pilot light means ready. A green pilot light means the flash hasn't fully recycled yet. Quick Flash will allow the flash to fire, but at a lower power. This can save you since it's throws some light on the subject even if it's not enough.

And it's another green light that's used to tell if flash power was sufficient, when using E-TTL II.

Thanks for all the input, when I double checked the cameras again I thought that I had all the settings the same....then after some digging into the settings I realized that the flash control settings in-camera on the 6D were set to Average, rather than Evaluative. As stated above, I think that was causing a slightly more powerful flash output and putting a longer delay on the recycle. I shot several homes today and yesterday and I did not run into this issue either day. So, that appears to be the magical setting that was throwing things off.

Thanks for taking the time to read the post and give suggestions, I really appreciate it!