Greg
Thanks for sharing your photography tips with us. I have tried, without much success, photographing hummers using my Canon 20D built-in flash to trigger one Sigma EF500 DG Super slave unit. Granted this is a very primitive setup compared with your more elaborate system of multi-strobes and wire release. I have several questions for you:
1. Every time I activate my built-in camera flash, it is set for the default 1/250 second. I have experimented with manual controls and the circular "joystick" to no avail. Does it matter if the actual camera speed is 1/250 sec? yes, it matters. For a sharp flash exposure, you want ambient light to be two stops underexposed, or darker, to avoid ghost images] use canon also, but have a d60, a 10d and a 5d. From what I know of the canon system, it only uses the on-camera flash in automatic mode. I suspect your flash only works in automatic mode, sets the shutter and aperture automatically. That's not the desired effect. The best you can to is put your camera on full manual, and put your flash in the hot shoe, or use a sync cable
2. Do you use your in-camera flash to activate the slave units or do you use the 580EX?
I don't use in camera flash. I use 2 550EX slaves and a 580ex master when I use canon flashes. I set them on manual 1/128th power, 105mm focal length, and place them extremely close to the feeder. I only use them when feeder and background are both in shade. (That's one of the reasons I use a white cardboard background behind the feeder on most occasions. I can keep it shaded. I have an off camera shoe "extender" cable that I use for the master. This lets me use all 3 flashes to good effect. Thus I need 4 tripods, generally, in tight quarters. A nice frame for camera and flash would be very handy.
If I weren't using the canon system flashes, any PC sync cable to connect the flash to the camera should do. My camera syncs at 1/200 sec, I believe, so I presume yours syncs at 1/250sec.
3. Does the Canon 580EX speedlite have more flexibility there?
Not really. It has a little more power than the 550ex flash, but mainly the 550 and 580 have a 1/128th power setting which provides a very brief flash. I think I measured it to be about 1/20000 second.
So far, I position for frontal lighting (sun directly behind me and 90 degree to bird's side, with the slave unit at a 45 degree angle pointed towards the birds front, and at same subject height and distance about 4.5 ft away (overexposed at ISO 400). I am aware of FEC and try to reduce flash duration but my flash LCD doesn't show me if I'm doing it right.
So far, what am I doing wrong? Having your equipment is out of the question.
Any advice is much appreciated.
Dennis