Can anyone help me with this.
580 EX II on camera with radiopopper transmitter.
two 580 EX II on a mono pod both in slave mode.
Frist 580 has a radiopopper receiver.
Second does not have a radiopopper but is connected to the first by pc connection.
Here is my question will the second 580 recivied any ETTL commands from the first via pc connection.
Thanks in advance
Stephen
1) The PC on the 580exII is input only.
2) Its a simple trigger circuit for manual flash and doesn't carry ETTL info
Have you ever tried the Canon system without the RP? That would solve your problem because both slaves would see the coded optical preflash of the Master. See http://super.nova.org/DPR/Canon/MultiCanon/
The other possible solution with the RP would be to jury rig a light pipe between the to flashes from the single output of the RP.
The RP doesn't work like that. It is in addition to the light signals sent as regular wireless ETTL and not in replacement of as with the new PW system.
The RP system works by interpretting the light signals from the ETTL master, encoding and sending them as a radio signal and the transmitter coverts the signal back into light directly into the ETTL slave sensor. However the master flash is still firing the light signals whether a RP is attached or not.
As such, set your 2nd 580ex to ETTL slave mode and fire away as usual. The first slave with work using the radio signals and the 2nd using the light signals sent from the master.
azroin wrote:
...580 EX II on camera with radiopopper transmitter.
two 580 EX II on a mono pod both in slave mode. ...Frist 580 has a radiopopper receiver. Second does not have a radiopopper but is connected to the first by pc connection.
...will the second 580 recivied any ETTL commands from the first via pc
Beni wrote:
...set your 2nd 580ex to ETTL slave mode and fire away as usual. The first slave with work using the radio signals and the 2nd using the light signals sent from the master.
If one of the slaves on the lightstick works off the optical signal from the master, why would he need the Radio Popper at all? The other slave would also work with the optical signal.
The whole point of using radio links is for those occasions when optical triggering won't work reliably.
Firstly I was correcting the wrong advice given about the way RP works. Secondly wireless ETTL works in relay as far as I know so there is a good chance it will work even if the slaves can't see the master flashes signals. Thirdly it is the only option to get wireless ETTL on the 2nd unit. It certainly won't work with the pc cord.
Beni wrote:
"Firstly I was correcting the wrong advice given about the way RP works."
What wrong advice? Chuck was the only poster before you, and he said that a PC connection is not an E-TTL connection, which is true, and that a light pipe to split the RP's optical signal might work, which is also true.
"Secondly wireless ETTL works in relay as far as I know so there is a good chance it will work even if the slaves can't see the master flashes signals."
I'm pretty sure that you are mistaken on that. Even if you are correct, that's not what you said in your first post. You said, "the 2nd [slave will work] using the light signals sent from the master." There's nothing there about "relay."
"Thirdly it is the only option to get wireless ETTL on the 2nd unit. It certainly won't work with the pc cord."
Chuck already told him it wouldn't work with the PC cord.
However yours is not the only option. Chuck gave a reasonable DIY option: "The other possible solution with the RP would be to jury rig a light pipe between the [two] flashes from the single output of the RP."
Mounting the RP between the two flashes, and then running two strands of fiber-optic material from the RP's illuminator to the receivers on the flashes could, if properly done, work reasonably well; after all, the Radio Popper P1 receiver uses a fiber-optic bundle to get its signal from the box to the flash unit's sensor...this would simply be an extension of that.
The most reliable option, of course, is to get another RP.
BrianO wrote:
What does that mean? I'm quite familiar with the PX. It's not relevant to your previous posts in this thread.
It doesn't use fiber optic!! Rigging up some sort of non native fiber optic cable solution to the newer sensor makes no sense whatsoever given that if the flashes are anywhere near close enough to do such an annoying, error prone and unreliable solution then they would work anyway using optical Wireless ETTL BY RELAY. The PX needs to be right over and touching the flash sensor, not sure how you would put a fiber optic cable over it.
You ask for solutions, I've given a simple solution for the problem in hand, if the slaves are close enough for a pc cord then they're close enough to trigger each other optically. If you decide that working with masking off the sensors and running a dual fiber optic cable not designed for the system from a PX not designed to work with fiber optic with all the associated taping, fustration, etc is a better solution then bully for you.
Your pedantic picking of my threads to prove yourself right is getting tiresome. Maybe you should be getting more familiar with the PX than you claim.
Who said it did? Not I. Not Chuck. But a DIY fiber optic cable attached to the back of the PW would work as well as the fiber optic on the old P1, if done right.
"...they would work anyway BY RELAY."
You haven't demonstrated that. Link or reference?
"...The PX needs to be right over and touching the flash sensor, not sure how you would put a fiber optic cable over it."
Tape? A DIY housing? It's only limited by your imagination.
Besides, the OP never said anything about PXs.
"...Your pedantic picking of my threads to prove yourself right is getting tiresome. Maybe you should be getting more familiar with the PX than you claim."
Maybe you should get your facts correct before you "correct" other people.
Have you ever tried the Canon system without the RP? That would solve your problem because both slaves would see the coded optical preflash of the Master. See http://super.nova.org/DPR/Canon/MultiCanon/
This is WRONG because you don't need to remove the RP to use the optical system! This sentence specifically denotes that without the RP both slaves will see the preflashes of the master. My point is that the RP has no effect whatsoever on the preflashes and they are just as visible with it mounted.
Care to deny that?
Suggesting a DIY solution in a situation that doesn't need it due to a lack of understanding of both the details of the OP and the RP system in question needs correction. Defending someone elses mistake and flaming the correction is immature in the extreme. The P1 worked badly enough with the fibre optic cable it was designed to use, actively pushing a solution which at best will be a pain in the neck in the face of a superior suggestion.....you actually ever shoot in the field when it's your money on the line?
Beni wrote:
...actively pushing a solution which at best will be a pain in the neck in the face of a superior suggestion...
What superior suggestion? I asked you why one would want to have one slave on a radio trigger and the other on an optical trigger, and you didn't answer the question.
If you can demonstrate the superiority of that setup I would be most interested.
Giving advice is not a contest to see who can piss the furthest, so lets tone it down and keep it civil eh?
I'm quite familar with old and new versions of the RP.
The old one required gaffer taping the optical transmitter of the receiver unit to the sensor window of the slave flash.
For the new version as originally issued required masking off the entire slave sensor with a mask supplied by RP. The mask had a hole in it which aligned with the optical transmitter (LED?) in the receiver. The set-up procedure, per the video on the RP site, also required attaching a donut shaped light shield to the receiver. So with the new version as currently implemented the slave sensor is completely blocked and would not be able to see the optical signal from the Master. The same would be true with the original version if the tape holding the transmitter probe completely covered the sensor window on the slave.
RP has designed a new stand mount for the slave which may eliminate all that masking and donut nonsense, but it also appears to completely block the sensor window on the slave. This modification is not yet shipping.
The OP didn't state which version of the RP he was using and I can't read minds, though I sometimes do try to read between the lines of questions. At best my suggestion is a stretch, but I was just throwing out an idea to try.
I also suggested trying the Canon system as designed because it wasn't clear he'd tried that or considered it as an option. As others have observed if one of the slaves responds to the Master there's really no need for radio triggers at all. I'm not anti-radio, I just think its foolish to throw money at a problem which may not even exist based on anecdotal accounts of Canon performance; i.e. jumping to radio triggers for Canon flash before even learning how to use the Canon system effectively.
Beyond that if the task he's trying to do requires the power of two 580ex flashes in tandem on a mono-pod my advice would be that the Canon flashes probably are not the best tool for the job. For the cost of two 580exII and RadioPopper he could buy a Quantum or an AlienBee with Vagabond.
