Originally posted by ryan s Reverse polarity = most flashes use the bottom, center pin as the +, and the little metal pieces inside the "shoe slot" are the ground. Some are the opposite and use the center pin as ground.
And on this issue, I'll say...come on people. I know old flashes are cheap/free...either sell them and buy one of the boatloads of good flashes for under $100 (Nikon SB series...love my 24)...buy a Safe Sync...buy a hotshoe -> PC adapter...buy a wireless flash solution...something.
Don't risk a mutli-hundred dollar camera with a free flash. The worst that could happen is you kiss your flash circuits goodbye, and we'll probably laugh and say "told you so." Wait...that's not very good
I think your suggestion is appropriate for majority of the people out there. But for the sake of the new camera users who do not know any better and just happen to have one of those old flashes sitting around and for the sake of the real tinkerers who like to do weird and creative things with their old flashes, Pentax should publish the maximum trigger voltage and current and write a clear caution statement regarding older flash in the manual. This should actually help them sell more cameras to those tinkerers and prevent, to a certain degree, the uninformed newbies from blowing up their camera.
Note: I think most hotshoe to PC adapter may not provide high voltage protection. If your camera has a build-in PC port, then the PC port is protected from "high" voltage. But this protection does not extend to its hotshoe.
Last edited by ma318; 01-24-2010 at 08:50 PM.