Paul C. Buff, Inc. Technical Forum

I have what is probably a VERY basic question, and since I am new to this, I suspect there is some basic element that I'm missing. I'm shooting with a Canon 7D sync cord is directly connected to Alien Bees B800 which trips just fine when the camera fires. I have two other Alien Bees B800 that test fire just fine but do not fire as I suspected they automatically would when the first light fires. Is there some setting I'm missing?

If the hardwired flash is firing, the other two lights should fire provided a-they have nothing plugged into the sync jack, and b-they are able to "see" the main flash (either directly or reflected). The slave eye is on the back panel of each light. If the slaved lights have large softboxes, or there are walls that are really dark or far away (or not present), the light may not effectively bounce into the light. Also, a narrow beam spread can limit where the master light falls.

Something else to note: if you are using a speedlite in the hotshoe of the camera, its preflash would fire off the slave units too early, which would then not appear in an image. The master flash would have its slave eye locked out, and would fire on time.