A simple title for a simple question. I'm curious. It seems like most flashes will fire, in at least some mode, on most cameras. Even my batteryless TLR has a flash sync socket. I also hear that some flashes will damage some camears, that cannot take the voltage of the flashes. So, how does this work? Does the camera simply short out the flash when it fires, either by shorting the coaxial flash sync socket or shorting between the center pin and the hotshoe contacts? I tried firing my SB-28 by shorting the center pin to the side, but it didn't work. Also, why is it called a PC sync?