Off-Camera Flash
Using Off Camera Flash
Most people who work in a photo studio and use strobe or flash as their lighting source, typically do not use the camera's flash, due to its harsh and unflattering effect. In camera flash has its limits of how much control the photographer has through flash exposure compensation, and (more often than not) cannot trigger other flash/strobe units.
So how does a photographer signal the flash to fire when clicking the shutter button on the camera? Answer: Wireless trigger.
An electronic device that can be attached to the camera's hot shoe, signals the radio receiver to fire flash units attached to them, allowing the photographer freedom to move around and the flash units as well (if desired).
Wireless triggers comes in different shapes, sizes, and costs. You can find them at your preferred photography equipment supplier.
The only downside to wireless triggers is that they are prone to interference, since they utilize radio signals. You may have to toggle your trigger to get the best channel without any interference during important shoots.