A well-waited-for episode on flash photography. This is the first of a three videos series on how to trigger External flashes. Here we…
learn the easiest and most economic way of achieving that.
Most DSLR have a built-in popup flash which when enable is meant to change the expose by providing some light. That same popup flash can also be set to act as a trigger by emitting some light beam, not powerful enough to change the expose but perfect to trigger external flashes (Speedlight).
This is a clever system as I can set my commander flash to either act as a trigger only or also as a flash:In the latter mode I can even introduce the notion of ratio between flashes. I can, for example, set the external flashes to be four times more powerful than the built-in popup flash.
The number of external flashes that can be triggered is, I believe infinite) as long as your commander flash (the built-in popup flash) and your external flashes are all using the same channel. Here is have used the built-in (trigger), the Speedlight behind the model and another Speedlight on the right side of the model.
The built-in popup flash is a rather powerful feature, but it does come with some drawback. Because it relies on a light beam to trigger the other flashes, it requires a line of sight, so if your flashes are behind a wall, they may not be triggered. Also, the built-in flash has not a lot of power so if your camera was to be 30 meters away from your flashes it is possible they may not receive enough light to be triggered.
I do believe this feature is still better than using cable as most consumer DSLR do not have a PC port built-in which means one needs to purchase some adapter that mounts on the hot-shoe and same goes for cheaper flashes. Finally overall, dealing with cords is annoying both for distance reason and for being another source of hazard.
In the next episode, we will see how to trigger external flashes via Infrared.