During a recent studio shoot of our four-month-old daughter Anna, Svetlana and I used a Canon ST-E2 transmitter to simultaneously trigger a Canon Speedlite 580EX II flash and a pair of AlienBees B800 studio flashes.
The ST-E2 is specifically designed to trigger Canon’s Speedlites and to utilize ETTL (Evaluative Through The Lens) metering. In the ETTL mode, the Speedlite emits a brief pre-flash, during which the camera determines the exposure. The pre-flash is followed by the main flash.
A B800 studio flash can be triggered wirelessly by the optical slave cell, which is built in the back of the unit’s control panel. When the slave cell detects an external flash, it immediately fires the unit.
The potential problem with using the Speedlite to trigger the B800s is that the studio flash units are designed be used in the manual metering mode. The ETTL pre-flash causes the B800s to fire too early, which results in a dark image. If the output of the B800 is set to a low power, the unit can recharge and fire again during the main flash of the Speedlite, in which case the image will be exposed correctly. Thus, the dark images appear to occur intermittently, which make this problem very annoying and difficult to troubleshoot.
Here are potential solutions that do not involve wired triggering or purchasing radio transmitters/receivers (such as CyberSync or PocketWizard):
- Not using an ST-E2, but mounting the 580EX II Speedlight directly to the camera and switching it to manual mode.
- Covering the contacts on the ST-E2 with a piece of tape or paper so that only the central pin makes contact with the camera’s hot shoe. This simple modification will disable the ETTL pre-flash.
Please share your own solution if you have used a similar lighting setup.
See more photos of Anna.