I just discovered the existence of CaveChat. Looks good, but just one more thing to take up my time. Won't tell my wife about it.......
As the purveyor of Firefly Slaves one would assume I have a certain bias towards them. I do in the sense that they work the best of all the slaves I've tried over the years or I wouldn't be selling them. I also have several Wein slaves I've worked with since the early 90's and do occasionally use them when I'm short on the Fireflies. The Weins work well but tend to be somewhat temperamental, false-firing when touched or tapped lightly or if they are damp. They won't fire a flashbulb as a general rule. Fireflies will do that for you. I was also a bit dismayed by the choice of connectors: PC or prong on the Ultra-SSL version, neither of which are particularly good for cave photography. The version with a hotshoe doesn't have as much sensitivity as the Ultra-SSL slaves.
The Firefly 3 for digital cameras is now available through me in the US. It is more expensive than the FF 2 but has considerably more electronic components and complexity. It is, however, less than the Wein digi-slave by cost comparison. Contact me at
pjcaver@gwi.net for more info about purchasing. This is not the place for me to advertise it...
Now, that leads to a basic problem with using digi-firing slaves. The digi-slave is making up for a basic problem in certain digital cameras, which is the ability to turn off the double or triple preflash. If your camera is doing the preflash, it is using through the lens metering (TTL) and is setting the aperture based only on the on- camera's flash. It won't pick up the added external flashes' output, causing it to likely be overexposed. That's one problem.
The second problem involves using multiple flashes distributed in a large area. If the on-camera flash is the trigger and the nearest digi-slaved flash is set off by it, how about the other slaved flashes that are farther away or around corners? Do they respond to the (usually) weak on-camera flash or to the digi-slaved flash nearest the camera? If it's the on-camera flash will all its preflashes, you would have to use all digi-slaves throughout the entire array of external flashes. If it's the digi-slaved flash, then you would have to use regular slaves for the second third, etc slaved flashes. If it were a perfect, consistent world, one could determine what works best and go with it, but we all know how incredibly finicky cave photography is in the very best of circumstances. As such, using digi-slaves is not really the best option for cave photography purposes unless you plan on using only one external flash. Ye Gods, I've just shot myself in the foot!!!! javascript:emoticon(':exactly:')
I say all this just to point out that a fully manual camera with the ability to turn off all the pre-flash gibberish is really the best way to go. The workaround of using a digi-slave is a patch at best and one that can lead to frustration and accusations that the slaves are faulty or not working as they should. Use digi-slaves with caution if you have to use them at all. For my money, I'd get the fully operable camera instead.
pjcaver