The range of wireless off-camera flash systems, from simple to sophisticated, allows you to fire single or multiple flash units remotely without tripping over long wires or worrying about fragile connections. Wireless flash has so many advantages over hard-wired flash it was quickly adopted by advanced amateurs and pros ranging from wedding warriors to studio, industrial, and sports photographers.
Let's look at the different kinds of triggering systems:
Flash-activated slaves are the oldest and least expensive type of wireless flash, but unless you're working in a studio, are also the most problematic. That's because any flash that's visible in the area you're working will trigger flashes that use white light slaves. If you're shooting a wedding with slaved flash units and Uncle Joe decides to take a few snapshots, his puny on-camera flash could set off your slave units at a crucial moment, draining your batteries faster and causing headaches all around. Fortunately, there are plenty of other choices available.
Digitally encoded triggering
To get around the aforementioned limitations of white light slaves, camera manufacturers and independent flash equipment makers have come up with a number of ingenious triggering systems. Many use digitally encoded pulses of either visible light or infrared, insuring that slaved flash units will not be accidentally fired by other flash units that aren't in the system. Virtually all of these systems provide several channels so photographers working in a studio, arena, or wedding venue can even avoid their units being fired by others using the same brand of equipment.
Systems using encoded infrared may offer triggering units that emit no visible light, or flash units that can be set to send out an infrared triggering beam without firing. This allows greater flexibility in arranging lighting setups where direct flash from camera position may not be desirable.
All light- or IR-activated wireless systems require an unobstructed path between the direct or bounced triggering beam and the receiving flash, but some provide a test button on the master flash so you can check whether the slaved units will fire before taking the shot. Encoded triggering systems work very well over moderate distances, but are not as effective in vast ballrooms, black-painted nightclubs etc.
The big advantage of radio-controlled triggering systems is range. All are capable of firing a flash up to 1,000 feet away and some will work at greater distances –up to 1,600 feet. They can also fire a flash in another room or around corners, or in a non-reflective environment where no bounced light or IR can reach a light-activated sensor.
The most sophisticated radio controlled units provide up to 32 channels, so sports photographers shooting with legions of other pros can avoid having their remote flashes inadvertently fired by others.
Disadvantages of radio-controlled sending units: They're usually larger than other types of slave units, require battery power, and may not provide TTL operation or flash ratio settings. A more important factor, especially for amateurs on a budget is cost. Radio-controlled wireless systems are generally more expensive than light- or IR-controlled units. A big plus point is that they can work with a wide variety of high-powered professional flash units, which is why pros favor them.
Specific wireless flash systems compared
Now that you have a good basic concept of how wireless flash units are triggered, what follows is a brief description of the basic specs of a number of leading camera-brand and independent wireless flash systems. This is not intended to be an exhaustive list, nor is it possible to describe each and every element or feature of these systems in detail in a single article, However, this comparison of system highlights should help you choose a wireless system that's most suitable for your type of photography
But you are not necessarily tied to one system. Check out this video on AdoramaTV, in which Mark Wallace shows how you can actually mix and match Canon and Nikon (and, presumably, other) wireless flash systems using wireless transcievers and transmitters. In the following AdoramaTV tutorial, Mark Wallace explains:
Canon wireless E-TTL system
This system uses brief digitally encoded light pulses, either visible or infrared depending on the master (triggering) flash used. Canon's built-in flash units are not part of the system, and it requires at least two wireless-capable flash units to work. The E-TTL system is capable of firing up to three groups of slaved units via the master flash, and to fire them at different power levels (lighting ratios) using a pre-flash system, Based on the pre-flash output of each group, the camera calculates what the final flash output should be using both the pre-flash data, plus user-defined group ratios and flash exposure compensation settings. This all occurs virtually instantaneously, so there is no time lag.
|Canon ST-E2 transmitter controls all wireless Canon flash units.
You can also specify any one of four channels for flash control, each capable of controlling up to three groups of flash units, and check that all are within transmission distance by pressing a test button. The Canon Speedlite 580EX II can be used as a master or slave, and you also set it to trigger slaved units without firing itself (like the Canon ST-E2 wireless transmitter). The system includes two ingenious EX macro units, the MR-14EX and the MT-24EX, which have two flash tubes that can be set to provide lighting ratios by assigning them to different groups. The Canon Speedlite 430 EX II, little brother of the 580EX, also works with the E-TTL II system that includes distance, reflectivity and subject size in calculating the flash exposure. The Canon system has been steadily improved since its introduction in 1998.
Nikon Creative Lighting System
Nikon's i-TTL wireless flash system employs pulsed modulated light for triggering the slaves in its Speedlights using either the 5-segment TTL flash sensor or and RGB sensor which, along with data from the 1005-pixel Color Matrix Metering system, controls the overall exposure. The system provides four channels, and it can fire up to three groups of slaved flashes, and control the output level, mode and compensation value of each group independently to obtain a wide range lighting ratios and effects. When using the versatile top-of-the-line Nikon Speedlight SB-910 as the master flash, the system has a range of over 33 feet.
Key elements of the sophisticated Nikon system include: The Nikon Speedlight SB-700 (ISO 100 Guide No. 92 at 28mm) and the SB-910 (111.5 feet at 35mm setting). Two sophisticated wireless close-up units, the Nikon R1 Wireless Close-Up Speedlight (for amateur and enthusiast-level Nikon DSLRs with built-in flash) and the Nikon R1C1 (for pro Nikons without built-in flash) offer ratio control and i-TTL Balanced Fill Flash. The Nikon SU-800 Wireless Speedlight Commander uses a pulsed infrared system to control older Nikon SB-900 or SB-600 flash units.
In this AdoramaTV review, Mark Wallace shows how Nikon has improved several features on the Nikon SB-910:
Radio-controlled wireless flash systems
Quantum Radio-Controlled Wireless Flash System
The Quantum wireless QTTL system links Quantum Qflash 5d-series strobes wirelessly using Quantum QTTL Adapers with a FreeXWire Transmitter to send radio commands to one or more remote Quantum FW-7Q FreeXWire receivers connected to Qflashes. There's also a new, compact FW7Q receiver that plugs directly into Qflash 5d- and 4d-series units, and a Quantum FreeXWire FW8R receiver that connects to Qflash units for wireless TTL, The latter is claimed to receive wireless flash sync for any type of shoe, handle-mount or studio flash. Quantum's system is also said to work with all popular TTL systems including Canon's E-TTL and E-TTL II, and Nikon's i-TTL using D and Dw Series adapters.
PocketWizard Radio Control System
PocketWizard has become a standard radio control system for many pro shooters. The PocketWizard is a digitally encoded radio transmitter system that can be used for wireless flash and firing cameras remotely at distances up to 1600 feet. The PocketWizard Plus II (right), an all-in-one transmitter/transciever, has auto-sensing transceiver trechnology to determine which mode (transmit or recieve) to set itself. (Look for the Pocket Wizard Plus III, which adds selective quad zone triggering, to arrive soon.)
The PocketWizard MultiMAX Transceiver (right) features Wireless Transceiver Technology, which eliminates the need for a separate transmitter and receiver setup. Each MultiMAX provides the capability to send and/or receive digital signaling by a flip of a switch, similar to personal communicators. Among many advantages, a photographer can select between a transmitter or receiver mode as shooting assignments change. The MultiMAX provides the capability to send or receive digital signaling by a flip of a switch, eliminating the need for a separate transmitter and receiver. Easy to read backlit LCD panel indicates which mode the MultiMAX is set for in all lighting conditions. It can automaticalluy confirm radio triggering up to 1600 feet, and can work in 32 digitally coded channels.
All PocketWizard Digital Radio Receivers are fully compatable with Sekonic's L-608 and L-358 exposure meters configured with the plug-in digital radio transmitter module.
Metz, based in Germany, is a respected independent flash manufacturer of long standing that offers its own "cross-platform" wireless flash system. Typically the Metz flash on camera is fitted with a dedicated SCA-3083 TTL module (available for Canon, Nikon, Olympus, Pentax, Mamiya, and Hasselblad). When the flash fires, the module sends a digitally encoded optical signal (of a blended frequency not in the visible spectrum) that can only be read by auxiliary slave-equipped Metz flash units used in the lighting setup. Other brands won't fire the Metz flashes and the there are two channels to prevent accidental firing by other Metz units. The system is designed to provide even illumination, and lighting ratios cannot be set via the module but only by placing flash units at different distances, using ND filters, or employing manual exposure.
Metz Wireless Flash System
|Metz 76 MZ-5TTL, with a guide number of 250 at ISO 100, is one of the most powerful wireless flash units available.
Plus points of the Metz system include: TTL operation and user-friendly setup and controls. Key elements in the system: The powerful handle-mount Metz 76 MZ-5TTL with 3D multi-sensor measurement, built-in SCA 3083 module, and a maximum ISO 100 Guide No. of 250. The compact Metz Mecablitz 28-CS-2 aimed at compact digital cameras (it weighs only 5 ounces) has a maximum ISO 100 Guide No (with tele attachment) of 92. The SCA 3083 module, which can be used as a slave trigger, a slave trigger with flash suppression, for wireless TTL or in automatic flash control slave mode.
A popular wireless infrared slave system
|The Wein SSR and SSR Junior have strong sensors that block other people's flashes from accidentally triggering slaved units.
Wein (a division of Omega Satter) offers both a basic open channel infrared (IR) and a coded IR slave trigger system. The most popular and economical Wein units are the open channel SSR and SSR Junior systems that use infrared transmitters and strong white light receivers to provide wireless triggering in settings where other peoples' flashes are not a concern. The infrared slave trigger can mount on any hot shoe or be fired via a PC contact. Infrared fires the sensitive receivers without affecting film or digital exposures. The Wein Pro-Sync, a coded IR system designed for use at weddings and other events with multiple photographers, is available in one- and two-channel versions, each with a transmitter and receiving unit.
Article updated 3/15/12.