Cybersyncs, Canon 5D, and 580EX's...Big Problem

So at wedding receptions I use the 5D with a 580 mounted, and I also use a Cybersync trigger velcro'd to the side with a mini-sync cord going into the sync port of the 5D. With the cybersync, I like to trigger a couple of 580's popping on the dance floor.
However I've encountered a problem. The off camera flashes don't seem to pop every time when I have the on camera flash turned on. When I turn off my flash, the OCF's pop every time. Then sometimes the on camera flash won't fire, but the OCF's will.

Last week I was using ETTL on camera, and popping the OCF's just fine, every time. This week they were troublesome.

Can anyone explain what's going on here, or what I can do to fix this? PCB says you have to shoot with the on camera flash set to Manual, but I swear I was using ETTL last week.

Here is a picture of the setup in case my explanation wasn't clear. It does the same on the 5D and 5DII. Quite vexing.

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Just throwing this out there, but it could be RF interference by the flash disrupting the signal from the trigger.

Sounds like RF interference indeed. I don't know if the Cybersyncs can, but switch to a different channel and see if that helps.

Also try attaching to the upper section of the flash head where you have the Velcro strip. This gets it away from the electronics in the flash head and might be enough distance to stop the interference.

You could also been getting some interference at the new venue maybe?

Does your set up work at your home???

IIRC only the 580EXII has the high radio interference.

^ This (I hear) is indeed on the EXII on the Pocket Wizards. But we were getting inconsistent pops on both our EXI and EXII.
I was thinking it might have been some interference at the new venue, but I'm not sure. I'll have to run a controlled test at home.
Like I said, Paul C. Buff and Company said that you have to use the On Camera flash on Manual for it to work. Can anyone confirm or bust this myth?

We use a similar setup at wedding receptions - (2) off camera flashes (430 exII's) connected to CyberSync Receivers and set to manual. On both our cameras we each have a 580 exII and a CyberSync Transmitter connected to the sync port on the camera. We attach our transmitters to the top of our on camera flash. Our on camera flashes are set to ETTL and we adjust the flash exposure compensation to control the light coming from our on camera flash. The remote flashes pop every time.

Unless of course I forget to enable the custom setting on the remote flashes to stay on all the time. By default it goes to sleep after a period of time if you don't trigger it. If that happens then you just need to wake it up (I just cycle power)...or better yet adjust your custom settings to have it never go to sleep.

Yeah, the OCF's don't go to sleep as I put them in Manual and also on "Slave" mode. I am also sure not to have the On Camera 580 set to "Master". This is weird.

If you're using CyberSyncs, why do you put the OCF in slave mode?

klr.b wrote in post #12257492
If you're using CyberSyncs, why do you put the OCF in slave mode?

^This.

You don't need to set your off camera flash to "Slave" mode if you are using wireless triggers. Likewise, your on camera flash doesn't need to be set to "Master".

S-Man wrote in post #12250136
So at wedding receptions I use the 5D with a 580 mounted, and I also use a Cybersync trigger velcro'd to the side with a mini-sync cord going into the sync port of the 5D. With the cybersync, I like to trigger a couple of 580's popping on the dance floor.
However I've encountered a problem. The off camera flashes don't seem to pop every time when I have the on camera flash turned on. When I turn off my flash, the OCF's pop every time. Then sometimes the on camera flash won't fire, but the OCF's will.

Last week I was using ETTL on camera, and popping the OCF's just fine, every time. This week they were troublesome.

Can anyone explain what's going on here, or what I can do to fix this? PCB says you have to shoot with the on camera flash set to Manual, but I swear I was using ETTL last week.

Here is a picture of the setup in case my explanation wasn't clear. It does the same on the 5D and 5DII. Quite vexing.

I use the exact same set up (On Camera 550EX Flash set to TTL and 3 other Off Camera 550EX Flashes set to Manual with the PCB Cyber Sync System set on and around the Dance Floor) on the Canon 5D and 5DMII..... but I place my Transmitter on the top portion of the Flash. Don't know why, just felt that that was the best place for it. And I've never had a single miss fire or problems using the Cameras or Flashes in Manual or TTL Modes.

I put the OCF's in 'slave' mode so that they won't go to sleep. I don't know how to set the CFn. to stay on. :/

And for clarification, my on camera flash is NOT set to "master".

Maybe it was some interference. I'll try moving the trigger to the top of the head.

S-Man wrote in post #12261195
.....I don't know how to set the CFn. to stay on. :/

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