I'm afraid I have no idea what an SX50 can handle....
I know the older Canon SLRs and perhaps the early DSLRs were only rated for 6 volts. Current Canon DSLRs are rated to 250 volts, at least since the 40D time frame, I believe. Maybe earlier, but I don't know at what point Canon improved the SLR/DSLR line to handle higher voltage.
Point n shoots, though, I have no idea and don't know where to find out. You might try emailing Canon support directly. (This forum occasionally sees Canon reps and techs drop in, but is mostly Canon users and enthusiasts helping each other as best we can.)
There is a website that shows flash trigger voltages, but that's by no means a complete list or a rigorous testing of those on the list. It lists the Sunpak 611, but shows a later one tested to have 4 volt trigger voltage, while an older one was much higher at 190 volts. (I assume you have measured your own 611 with a VOM.)
So, I'm not really helping much. Inquire from Canon support about your camera's trigger voltage capabilities. If you are still worried about it, you could use something like a Wein SafeSync to protect the camera from excessive trigger voltage. Or use the flash off-camera with a radio trigger (but be warned that radio triggers often have a trigger voltage limit, too.... some I recently looked at are rated to 24 or 30 volts).
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Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & PRINTROOM
