580ex II ETTL w/ Pocketwizard??

[scottf2]

I'm wondering if anyone can shed any light on this (ha):

580ex II on a 5D (on the hotshoe), PocketWizard attached with pc to mini cable from PC port on camera to mini port on PW.

I use this configuration regularly at weddings to fire AB800s w/ the PW, and use the 580ex for fill. I usually shoot the 580 on manual, and this all seems to work fine.

At a recent wedding, I was playing around with using the 580 on ETTL, with some very strange results:

I could SEE the ABs firing (out of the corner of my eye, or when I just put the camera down and looked straight at them while pressing the shutter release) - but the LIGHT from the ABs was not affecting the photo at all - the exposure was purely from the on-camera flash.

My conjecture as to why this is happening is that the PC sync outlet is putting out a signal to fire the flash at the same time that the 580ex is firing it's pre-flash, and therefore the ABs are firing BEFORE the actual exposure.

To reiterate: it all works fine when the 580 is in manual, but not when it's in ETTL.

Can anyone confirm or deny this or suggest an alternate explanation? I feel like I've read about other people using this setup successfully.

Thanks,
Scott

[fashioneyes]

I believe in ETTL mode, a series of IR flashes fire to establish light levels before setting the power output of the 580 in ETTL mode. This IR triggers optical slaves in your case the ABs.

In manual mode the IR pre-flashes is not fired and the 580's true flash output triggers the ABs correctly in sync with the camera

[PacAce]

I'm wondering if anyone can shed any light on this (ha):

580ex II on a 5D (on the hotshoe), PocketWizard attached with pc to mini cable from PC port on camera to mini port on PW.

I use this configuration regularly at weddings to fire AB800s w/ the PW, and use the 580ex for fill. I usually shoot the 580 on manual, and this all seems to work fine.

At a recent wedding, I was playing around with using the 580 on ETTL, with some very strange results:

I could SEE the ABs firing (out of the corner of my eye, or when I just put the camera down and looked straight at them while pressing the shutter release) - but the LIGHT from the ABs was not affecting the photo at all - the exposure was purely from the on-camera flash.

My conjecture as to why this is happening is that the PC sync outlet is putting out a signal to fire the flash at the same time that the 580ex is firing it's pre-flash, and therefore the ABs are firing BEFORE the actual exposure.

To reiterate: it all works fine when the 580 is in manual, but not when it's in ETTL.

Can anyone confirm or deny this or suggest an alternate explanation? I feel like I've read about other people using this setup successfully.

Thanks,
Scott
How many AB strobes do you have. Since you used the plural form of "AB800", I'm going to assume you have more than one. Are they all hooked up to a PW unit? If not, what 400D_newbie said above would explain why the ABs not connected to the PW units would not affect your final exposure. However, the AB that's triggered by the PW unit should affect the exposure, though.

[scottf2]

Thanks guys - in this case, there was only AB800 one involved. I had two set up, but only one turned on. They BOTH had PWs plugged in, which disables the optical slave.

The optical slave would definitely be the right answer... except that I'm using PWs so the optical slave is not functioning (on the ABs, when you plug something into the miniphone sync jack, it disables the optical slave).

Scott

[Andrushka]

So the AB's are on PocketWizards? or being triggered by their internal optical slaves? if its the optical slaves, then you already answered your own questions


sorry - slow to the punch

[PacAce]

Thanks guys - in this case, there was only AB800 one involved. I had two set up, but only one turned on. They BOTH had PWs plugged in, which disables the optical slave.

The optical slave would definitely be the right answer... except that I'm using PWs so the optical slave is not functioning (on the ABs, when you plug something into the miniphone sync jack, it disables the optical slave).

Scott

Hmm, this is a real puzzler because the PC port only "syncs" when the main flash is fired, not when the pre-trigger flash is fired. :confused: :|

Have you tried firing the 580EX in manual mode to verify that things are still working the way they used to?

[scottf2]

Yup - it's a real puzzler!

Everything works as expected in manual mode. Has anyone actually used this particular setup in ETTL mode?

I would EXPECT that the pc sync socket would send out a signal when the main flash fires and NOT when the pre-flash fires, but can anyone confirm that is actually the case?

[PacAce]

Yup - it's a real puzzler!

Everything works as expected in manual mode. Has anyone actually used this particular setup in ETTL mode?

I would EXPECT that the pc sync socket would send out a signal when the main flash fires and NOT when the pre-flash fires, but can anyone confirm that is actually the case?

Have you tried cranking up the power of the ABs to make sure that you're not just missing seeing it because of the light from the 580EX overpowering the AB lights? (I'm just grasping at straws here.) :confused:

[René Damkot]

the optical slave is not functioning

Double check that to make sure.
(just fire a test flash with the 580 off the camera)

[picturecrazy]

You AB should fire at the same time as your real 580 flash. I use ETTL and PW light together extremely regularly and they fire at the same time.

Just to cross all t's and dot all i's, is the power on your AB high enough to actually make a difference in the exposure? Are you running on HSS mode with your 580?

[canonphotog]

Throw some gaffers tape over the optical sensor on your AB and try it again.

[scottf2]

Thanks for the continued replies. I'm 100% sure the optical slaves weren't firing the ABs - my second shooter was shooting at the same time, w/ a 580ex but w/o PW and she wasn't firing the flash.

The power was plenty high to show up in the photos - on all the manual shots, the light from the AB is very obvious. I had some shots where I had the AB in the frame just to check it, and it appears unlit (but while I was watching, I could see it fire).

I'm going to do some experimenting in the studio tomorrow and see if I can figure this out.

Scott

[scottf2]

Ok, I just tested this out further:

580exII on camera, PW connected to camera with PC cord, Sunpak 322 connected to PW off-camera (that flash has no optical slave).

In ETTL, my eye sees the off-camera flash fire, but the camera DOES NOT - I'm just taking a picture of the flash, and can clearly see when it fires and when it doesn't - I can only assume that it is firing at the same time as the pre-flash. I tried this on my 5D and 40D with the same results.

In Manual, everything works as expected - both flashes fire and are seen by the camera.

Picturecrazy: you said this combination worked for you - do you use this EXACT setup (5d/40D with 580exII, PW connected to camera sync socket)?

[scottf2]

Ok, I think I just figured this out:

I've got a Multimax and three Plus IIs - until last week I was using the Plus IIs, since i just got the MM. I mount the PW on the top of my flash using a PW caddy. When the MM is mounted like that IT DOESN'T WORK IN ETTL! If I pull it off the flash head and hold it away from the flash, it works. I assume the pre-flash is somehow causing the MM to misfire.

If I swap out the MM for a Plus II on the flash, it works every time in both modes!

I'm not sure if this is a fault with Multimax units in general, or my particular unit. Anyone out there with this combination of gear care to give this setup a try?

[PacAce]

I have heard of other people having issues of misfires when their PW unit (don't recall if it was MM, though) was very close to the 580EX II flash. They didn't have issues with other flashes so it might be 580EX II specific. I have a 580EX II and an MM unit that I can test. I don't have a caddy, though, but using something to hold the MM unit against the 580EX II should be OK, right? Which side of the flash did you have the MM unit attached to?

[scottf2]

Thanks Leo - the PW is attached to the top of the flash head you can see the setup in the attached picture (excuse the quality - it's a crop from a shot by my second shooter).

I'll try it with my 580ex (not II) to see if the same thing happens. I did notice in further experiments that moving the Multimax around a bit on the top of the flash head makes it fire or not depending on the exact position.

[PacAce]

One more thing. What version of MM do you have? To get the firmware version, first turn off the MM unit. Then press and hold the A key while switching the unit to Rx or Tx.

[scottf2]

Rev. 7.29 - bought it about a month ago.

[PacAce]

Well, I tried my MM which is also at rev level 7.29 and I could not get it to misfire at all. Since I don't have a caddy, I used two rubber bands to hold the MM against my 580EX II. I placed the MM on top of the flash just like you did. I placed it beside the head and even beside the body and I could not get it to misfire.

In your case, does the PW misfire consistently or only intermittently?

[scottf2]

Hey Leo - thanks a lot for doing those tests! Mine misfires pretty consistently, although not 100% of the time - it misfires about 90% - if I move it around a bit, it makes a difference as well.

I emailed Pocketwizard and pointed them towards this thread, so maybe they'll have something to say.

Thanks,
Scott

[jmb4370]

Try running your tests putting the PW that is attached to the flash at least 2 feet away from the flash. That is, use a long sync cable that is fully extended, so that the PW is physically a full 2 feet away from the flash head, and not right next to it, or touching it as with the Caddy.

From your post, I can not tell if your problem was more with the Plus II or the MultiMax. Can you repost your setup describing the testing with each of the PW's (Plus II and then MM), at making sure there is a physical separation of at least the 2 feet between the PW and flash unit.

There is a known RF "cloud" around the EX flash unit line, and I have been running some tests as to how the physical proximity of the PW to the flash head is affecting the transmission range of the radio set. There are RF shielding blankets, and other items that I have been working with, to try and increase the "in the field" real time improvements in the working range of the RF transmission.

[scottf2]

Thanks Michael - to clarify - I've only been having this problem with the Multimax, and only when it's attached directly to the flash head with the caddy, as in the picture above. If I separate it from the flash head by even a few inches, it seems to work fine.

I look forward to hearing more about your experiments and experiences with the "RF cloud" and what can be done to alleviate the problem. Switch to Nikon maybe? :rolleyes: