Just in case anyone out there may be contemplating using an older flash with their new digital camera as I have been doing, I thought I should pass on a caution I recently was made aware of. Apparently I got a bit lucky with my experimentation, as this web site reveals. I ran across it on the Strobist's blog (a very nice site for learning about using strobes in photography). Anyway, the first link there is for a list of a whole slew of flashes with their trigger voltages. Quoting from that page,
"Some strobes (and infrared strobe triggers) use high voltages in the trigger circuit. For mechanical cameras, this is fine — but many newer, electronically-driven cameras (especially electronic 35mm SLRs like the EOS or digicams — or for that matter, EOS digicams, like the 300D) can be damaged by excessive strobe voltages."If you can't read the flash in the photo above, it says that it is a Canon 188A, which, according to the trigger voltage page, uses 4.1V in the trigger circuit - less than the allowable 6V. This is an old flash that I had in my closet from my manual camera collection, and fortunately it is safe to use with my digital camera. Many other old flashes are not less than 6V, and are therefore not safe to use. So, consider yourself warned. Always check to make sure that equipment not made for your camera is safe to use with that expensive new piece of digital technology.