Digital Camera Accessories – The Remote Flash Trigger

As photographers we spend a lot of time playing with light. Light is our medium, we talk about its color, its quality, its size and its softness. And a lot of our talk is about how to change it. One of the first things that a novice photographer tires of and wants to change is the boring, flat light that their camera flash produces. While there are any number of devices that can filter or shape light one of the biggest groups of light changers are the remote flash triggers.

At the most basic level one of the fastest ways to change flash light from flat and boring is to move its position. If instead of having our flash shoot a head-on beam of light into the subjects face what would happen if we moved the flash up and to the right or left of the subject? The answer is that we get better and more flattering light. However once the flash is moved off of the top of our camera it loses the vital connections required to make it fire. This is where Remote Flash Triggers come to play.

While there are dozens of varieties of flash triggers available they all have one chief purpose: to cause the flash to fire at the precise moment that the camera’s shutter is open. This process is what we call “flash synch” and it has been around for about as long as cameras themselves.

Corded flash triggers attach to the top of the camera and have an electrical communications cord of from six inches to over 30 feet which on its other end connects to the flash through either a shoe or a plug of some sort. A flash cord is pretty much error free – if it works it’s good, if it doesn’t work throw it out and get a new one. However there is now a cord draped across the floor and the photographer’s movements are limited by how movable this cord is in its environment.

Here is an important detail to remember: while a flash cord may limit movement or present a slight trip hazard, with the right match of camera, cord and flash full TTL automatic exposure is maintained. With only a very few exceptions, remote flash triggers don’t offer automatic exposure.

One of the earliest remote flash triggers is the “electric eye” slave sensor. The slave sensor is still a popular accessory today. A slave sensor requires at least two flash units. The first flash unit sits atop the camera just as it usually does. The second flash is positioned where it is needed and a slave sensor is attached or plugged in. Multiple sensor equipped slave flashes may be used. The slave sensor remote trigger is simplicity itself; so long as the slave sensor’s electric eye can see the camera mounted flash, it will trip the slave flash every time that it “sees” the camera flash go off.

Another variation on the original slave sensor is a sensor system built around infrared (IR) controls. Why would anyone go to the expense of using an IR control? The photographer wants to trip one or more slave flash units without adding any flash light from the camera’s position. In the previous flash to flash slave setup the camera mounted flash is a part of the exposure and if the photographer is working handheld and change in position changes the main light in the exposure. With an IR controller rather than a master flash on the camera the photographer can roam at will.