Slave-to-Flash Compatibility

[robertwgross]

The trigger circuit is somewhat different on various flash units, so the recycling from one shot to the next can have different requirements. I suppose that you have read all of scottbergerphoto's sticky notes on these very things.

---Bob Gross---

[scottbergerphoto]

Canon EX Series flashes won't recycle with photoelectric slaves but will work with Pocket Wizards. It makes sense that there will be differences from manufacturer to manufacturer

[PacAce]

Something that I am encountering as I continue to downsize my lighting is the fact that some flashes just won't respond to a master when a slip-on hotshoe photoelectric slave is attached. It seems not to matter whether the slave trigger is a cheapo or an expensive one. Some flashes just won't respond to the trigger.

What's going on? Why will one photoelectric slave work on one flash but not the other? The Vivitars all work well with my hotshoe slaves, but my Sunpak pz4000 won't, nor will the Sigma DG ST.

All of the contacts touch, and distance isn't an issue.
From what I've read elsewhere, that's how they were designed. These flashes need to have "telemetry" data fed to them from the camera to work properly. For example, I read that the Sigma EF flash won't even flash if you contact the center "hot" pin on the shoe to the common pin at the side of the shoe. Not sure how reliable this information is but if it's true, then that would mean that you won't even be able to trigger them using the sync terminal (via a sync terminal to hot-shoe adaptor cable). :confused:

[scottbergerphoto]

From what I've read elsewhere, that's how they were designed. These flashes need to have "telemetry" data fed to them from the camera to work properly. For example, I read that the Sigma EF flash won't even flash if you contact the center "hot" pin on the shoe to the common pin at the side of the shoe. Not sure how reliable this information is but if it's true, then that would mean that you won't even be able to trigger them using the sync terminal (via a sync terminal to hot-shoe adaptor cable). :confused:
Canon EX Flashes will work fine with Pocket Wizards and a hot shoe to mini plug cord from www.paramaountcords.com. No camera data needed.
Scott