More than one light

Selecting the optimum way to control your off-camera Speedlites

Speedlites are used to illuminate subjects in the dark, but this is only the most basic way to work. Once the flash is taken off-camera the position of the light becomes important, and the notion that other lights are used to accentuate other parts of the scene are helpful too. With multiple flashes you need to decide how to control the lights. A sender unit on the camera gives freedom to control several flashes separately using groups. Whichever method you choose, it is always good to build lighting setups one light at a time.

Fortunately automatic E-TTL flash is designed to work with multiple flashes. Each unit needs to be assigned to one of three groups and the groups controlled in relation to each other. With two groups, A and B, the camera and flash system measures the light contribution of each group and automatically adjusts power levels to achieve your chosen ratio. Auto E-TTL flash is ideal for quick setups, or where the subject may be in a different position over a series of shots.

For precise control you should use manual flash exposure. Just because you decide the power of the flash you can still decide the power of up to three groups of Speedlites, and change it from the camera menu or the sender unit on your camera. Speedlite EL-1 and the Speedlite Transmitter ST-E3-RT version 2 add a flash exposure manual function that stores the previously used E-TTL power setting to use as the basis for a manual flash exposure.

An extra flexible group mode is available when working with Canon radio wireless units. Group mode allows up to five separate groups, plus each group can be individually set for manual exposure, E-TTL automatic exposure or switched off. If you were lighting people at a party, you might want to use E-TTL for the main light, but manual for a separate light that is illuminating a background behind them. With the ability to switch a group on or off, you can pre-configure multiple lighting setups and rapidly switch between them. Keep in mind that group mode requires the most concentration and button presses, so isn’t always ideal.

Multiple lights were used for this portrait: one for the main light on the model, another for the hair light through the smoke

When working with multiple lights, it’s common to assign them to groups and control them separately. Ratio control can balance up to three groups of Speedlites