How do I tell which older flashs are safe to use on digital cameras?

[Crazy Carl]

Hi;
I just switched from a 35mm to a Canon XSI digital camera. I still have alot of my old stuff that I would like to use if I could. How do you tell if the flash will work on my camera? They tell me that some will not, but not why or which ones. HELP. thanks for looking at this post.

Crazy

 

[Mike_E]

Hi Carl, I don't think your canon would live with much beyond 6Vs but someone around here should know for sure.

here is a list of sync voltages for most flashes to check yours against..
http://www.botzilla.com/photo/strobeVolts.html

 

[Crazy Carl]

Hi;
That was a site with some info. Thanks. I never knew why some flashs couldn't be used but know now. I have 4 flashs to check. I will be happy if I can get one of them to work. Thanks again.