The Flash Unit: Connecting to a Trigger
If your flash unit has a PC cord, you can connect the cord directly to your trigger. The end to connect is the male end, labeled Camera in the photo to the right. (This is the end that would normally connect to the camera.) You could simply cut off this end of the cable, strip the wires, and splice them to your trigger wires. This, of course, would remove your PC cord from service as a flash-to-camera cord. In order to retain this functionality, we recommend instead that you obtain a PC extension cord. These are sold at virtually any camera store. Then splice the trigger wires to the male end of the extension cord. The other end then plugs into the PC cord from your flash. (You may wonder why not just go down to Radio Shack and buy a PC cable end to connect to your trigger wires. The problem is that there's no convenient consumer source for these.)
[Here's a method of making connections that doesn't require any cutting or splicing.]
Many modern flash units don't come with PC cords. These units are dedicated to use with particular cameras and are triggered by the hot shoe of the camera. They typically have a pattern of several contacts on the flash foot, as shown in the photo to the right. (A non-dedicated flash would have only one contact in the center of the foot.) In order to use one of these flash units with a trigger, you can connect a flash-shoe-to-PC-cord adapter to the flash foot. One of these is shown in the left-hand diagram below. The flash unit would mount onto the shoe of the adapter. The PC cord would then be connected to the trigger. (For high-speed photography, one would not mount the adapter onto the camera's hot shoe.) Some of these adapters have 1/4" standard tripod threads in the base which would make it easy to mount the adapter onto a mini-tripod such as described in Accessories. The diagram on the right below shows the adapter mounted on the flash unit.
Adapter mounted on flash unit (note tripod thread in bottom of adapter)