Avoid unnecessary entanglements.
Long before consumers entangled themselves in their computer and home-electronics connectors, wires were the bane of photographers. They short out and otherwise malfunction, get disconnected, snap, and trip up photographers and assistants. No wonder that wireless triggers for flash units and cameras have become so popular.
Wireless triggers fall into three categories: optical slaves, infrared triggers, and radio triggers.
Optical slaves are devices that trigger a flash unit when they sense another flash firing. Optical slaving is widely used in studio flash photography, and virtually all studio flash units today have built-in slaves. Many accessory hotshoe-mount flash units also have built-in slaves.
Almost any flash can be fitted with an accessory slave. Among firms offering these, Wein (www. weinproducts.com) is known for its wide variety of slaves.
For a slave to work, it must be in the line of sight of the triggering, or master, flash. Slaves can also fire from a bounce off a wall, ceiling, or studio reflector. They can work over impressively long distances, although your yardage may vary depending on the power of the master, light path, or ambient light level.
Many accessory flash units use a preflash to determine autoflash exposure. If you use one of these as a master, the slaved units will be triggered from the preflash. Many slaves, however, can be set to ignore a preflash or preflashes.
Infrared triggers work invisibly, as they operate in wavelengths longer than those of visible light. As infrared triggers can be sensed by optical slaves, studio shooters use hotshoe-mounted infrared triggers to fire studio strobes.
Infrared triggering enables wireless through-the-lens (TTL) autoflash with single or multiple accessory flash units. The infrared trigger unit (the camera’s pop-up, dedicated accessory flash, or a dedicated hot-shoe trigger) can not only fire the remote units but also automate output according to your settings. Such systems have proved a boon for serious shooters who want alternatives to bulky location flash units.
Infrared masters must also be in the line of sight of the slave units, or at least in bounce range. They won’t work around corners or through walls.
That’s where radio triggers come in. Radio waves have no line-of-sight limitation, so radio slaves have become the choice of location pros. You need a transmitter to send the trigger signal, plus receivers connected to cameras or the flashes to be triggered. A transceiver can both send and receive.
Many radio triggers are available, but PocketWizard (www.pocketwizard.com) is the go-to choice for serious shooters. A chart on its website sorts out the dizzying array of PW units.
One thing about radio slaving: Typically, you get no TTL automation. This is no big deal; in fact, many strobe shooters find it easier to set manual levels on their multiple units than to work in auto. An exception is PW’s FlexTT5 transceiver, which can maintain TTL with Canon or Nikon flash units. And Canon’s latest Speedlite, the 600EX-RT, can be used in TTL as a radio trigger on a Canon EOS-1D x camera, as long as the slaved flash is another 600EX-RT unit.