RWR wrote:
Very few flashes of any brand ever made have dangerously high trigger voltages. The highest voltage I could find for Canon, the Canolite D, is only 185 volts. Nikons can handle up to 250 volts, I should think that Canons would be as well built. The trigger voltage of your 199A is a mere 6 volts, enjoy it!
The trigger voltage for most older flashes is listed here:
http://dpanswers.com/roztr/volt_finder.php
Here's another link that shows how to test the voltage yourself. I don't connect my old flash units directly to my cameras. I use wireless triggers, but still want to know the voltage.