| There are numerous third party flash units that will work with the camera. A few of them are listed below. However, the important thing to keep in mind is that of the flash trigger voltage. If the trigger voltage is high (above 6V), the potential is there for the flash unit to harm your camera. Before hooking any flash unit up to your camera, make sure you measure the trigger voltage. http://www.botzilla.com/photo/strobeVolts.html has quite a few listings of trigger voltages for different flash units.
Non-Canon flashes known to work with the camera:
* Recent Vivitar 283 and 285HV flashes. The older ones have high trigger voltages, so if yours isn't recent (~5 years old or so) make sure you take a measurement before hand.
* According to Paul Bleicher, the Metz 54 MZ 3 works as well
* Sigma EF-500 DG Super
marius |
Digital Photography FAQ's : 
Are there any detailed instructions online with tips on how to best use an E-TTL flash?