On this forum I recently learned abit about optical triggers. I currently have a 2 piece receiver/transmitter set. I want to add a 3rd flash. Can I can any cheapo flash that is compatible with my camera, throw an optical trigger on, and my transmitter will pick it up? Just wondering if that is how that works. I was told that I would have to buy another receiver/transmitter set to another flash, get a controller, or get a flash that has a built in receiver that is compatible with my exact receiver/transmitter set. But does optical trigger option could open me up to a world of using any flash I want that is camera compatible?