Originally Posted by dws1117 
How do you trigger a flash that is held off camera without using the on board flash as the trigger? Do I need to buy something? What am I missing?
You have two options, using a cable from the camera, (not sure if you need a hotshoe adapter or can use a camera port), OR using a radio transmitter/receiver. I purchased the Gadget Infinity Cactus radio transmitter/reciver and it works fine for my amateur use. The transmitter slides into the camera hotshoe and the receiver slides onto the "foot" of the flash.