I have read that one must put Electrical Tape on the bottom a metal device if you plan to put a Canon flash on top of it. (i.e., umbrella adaptor). This got me a little worried with putting a metal device (mount extender, etc) directly on the Hot Shoe of the 5D Mark II. Does anyone know if this is Ok to do? Does the metal on metal effect the electrical circuits?

thanks!
Michael

I had considered the issue, and tested it. I have been hanging a self built loupe off the shoe, using a metal shoe post scavenged from an old mic mount. I haven't had a problem. I would think there would be a warning in big print somewhere if it was an issue.