Older Flash

I have an older Vivitar flash that I used to use on my Pentax film camera and for the cheap price I actually had really good results with it. Will this flash work on my 20D? I remember reading somewhere that you shouldn't use older/incompatible flashes on DSLR's because it could damage the camera. Is there any truth to that statement?

Here's a link from the EOS Flash sticky thread:
Is my old flash unit safe for my new camera? Here's how to find out.

This web page has lots of info.

Your 20D should handle a flash trigger voltage up to 250v.

Do what I did. I purchased a Wein "Hot Shoe to Hot Shoe Safe Sync" for my Vivitar 283s. Plug this device into the camera's hot shoe and place the 283 onto its hot shoe. It also has a PC terminal if you want to move the flash off camera. I think I paid about $50 at B&H.

Hank E wrote in post #2996390
Do what I did. I purchased a Wein "Hot Shoe to Hot Shoe Safe Sync" for my Vivitar 283s. Plug this device into the camera's hot shoe and place the 283 onto its hot shoe. It also has a PC terminal if you want to move the flash off camera. I think I paid about $50 at B&H.

You can get a new Sunpak 383 flash that is nicer than the Vivitar 283 for only $80.00 that already has a very low sync Voltage (less than 6 Volts).

But as Curtis indicates, just measuring the sync Voltage is the best way to go. If it is less than 250 Volts for the 20D, then no need for a safe sync. Why pay $50.00 to avoid making a very simple measurement. If you do not have a Volt meter, most likely someone you know does.

Enjoy! Lon