I'm no means an expert so this is all based on what I've read, and my poor man experiments.
Other than a 580 as a Master ...
Assuming all strobes are 3rd party:
1) ST-E2 with optical sensors on the slaves (pins on the ST-E2 need to be taped up - also requires line of sight). Limited range.
2) 1 x 3rd party MANUAL master flash on or off cam connected via PC cord, or master digital flash with pre-flash turned off, slaves on optical sensors (like my set-up). Range limited only by distance from optical sensors to master flash.
3) Radio Slaves with a transmitter on cam (besides pocket wizards, there are also the cheapo Cactus slaves which will work with most units that can accept a PC sync cord, or one radio set which has been mentioned and recommended are the Elinchrome Shyports available here)
4) On board cam flash triggering slaves on optical sensors on slave units (need to switch off pre-flash).
Note: The ST-E2 has a pre-flash function, so for it to be useable with optical slaves, the pins need to be taped up. You loose AF assist when you use the ST-E2 that way.
Some users have reported varied success rates with Sonia brand optical slaves and their 580s.
Optical slaves work very much on contrast, so if you're using it in bright sunlight/outdoors in the open, you need to cover/hood up the receiving optical sensors unless you're using the OLD model Wein Peanut slaves (the new ones have been reported to be quite useless/unreliable, Don't know if the issues have been resolved)
Hope this helps.
If you're really tied for a radio, and can't rent a PW set, you could buy the Cactus units from Tagotech. Will send you a PM.
