As I mentioned in the last chapter, one of the chief objections to the use of electronic flash is the stark, flat look of direct/on-camera flash. But as flash wizard Joe McNally, author of The Hotshoe Diaries, has proven, small flash units can produce amazingly creative images when used properly.
The key to effective flash photography is to get the flash off the camera, so its illumination can be used to paint your subject in interesting and subtle ways from a variety of angles. But, sometimes, using a cable to liberate your flash from the accessory shoe isn’t enough. Nor is the use of just a single electronic flash always the best solution. What we really have needed is a way to trigger one—or more—flash units wirelessly, giving us the freedom to place the electronic flash anywhere in the scene and, if our budgets and time allow, to work in this mode with multiple flashes.
Most Canon “enthusiast”-level cameras with a built-in flash include internal wireless triggering capabilities using the on-camera flash. Because more advanced cameras like the R5 and R6 don’t have a flash to serve as a wireless sender (master), we must rely on using other flash units or add-ons to trigger our Speedlites wirelessly. Fortunately, most users of this camera are advanced photographers and can generally abide the equipment requirements that accompany useful wireless capabilities.
It’s not possible to cover every aspect of wireless flash in one chapter. There are too many permutations involved. For example, you can use an external flash, or the ST-E2 optical transmitter (or STE3-RT radio transmitter) as the sender. You may have one external “receiver” flash or use several. It’s possible to control all your wireless flash units as if they were one multi-headed flash, or you can allocate them into “groups” that can be managed individually. You may select one of several “channels” to communicate with your strobes (or any of multiple wireless IDs when using radio-controlled units like the EL-1 or 600EX II-RT). These are all aspects that you’ll want to explore as you become used to working with the amazing wireless capabilities.
What I hope to do in this chapter is provide the introduction to the basics that you won’t find in the other guidebooks, so you can learn how to operate the wireless capabilities quickly, and then embark on your own exploration of the possibilities.
This chapter is intended to teach you the basics of wireless flash: why to use it, how a dedicated flash or add-on controller can be used to trigger and manipulate additional units, and what lighting ratios, channels, and groups are. I’m going to provide instructions on getting set up with wireless flash, but, depending on what flash unit you’re working with (and how many you have), your specific steps may vary. The final authority on working with wireless flash has to be the manual furnished with your flash unit.
Here are some of the key concepts to electronic flash and wireless flash that I’ll be describing in this chapter. Learn what these are, and you’ll have gone a long way toward understanding how to use wireless flash. You need to understand the various combinations of flashes that can be used, how they can be controlled individually and together, and why you might want to use multiple and off-camera flash units. I’m going to address all these points in this section.
Your attached on-camera external flash can be used alone, or, if it has the capability to serve as a master or controller flash (not all Canon Speedlites do), now called sender in Canonspeak, in combination with other, external remote or slave flash units (now called receivers by Canon). Here’s a quick summary of the permutations available to you.
There are multiple ways of controlling flash units, both through direct or wired connections and wirelessly. Here are the primary methods used:
When used in these modes, the camera has full communication with the flash, which can receive information about zoom lens position, correct exposure required, and the signals required to fire the flash. You can also plug a non-dedicated strobe, such as studio flash units, into the PC/X connector on the R5, or into an adapter plugged into the R6’s hot shoe. Either PC/X connection is “dumb” and conveys no information other than the signal to fire.
In addition, some excellent wireless flash controllers that use IR or radio signals to operate external flash units are available from sources like Godox, PocketWizard, and RadioPopper. One advantage some of these third-party units have is the ability to dial in exposure/output adjustments from the transmitter mounted on the accessory shoe of the camera.
Canon’s wireless flash system gives you a number of advantages that include the ability to use directional lighting, which can help bring out detail or emphasize certain aspects of the picture area. It also lets you operate multiple strobes; with models like the old favorite 580EX II that’s as many as four flash units in each of three groups, or twelve in all (although most of us won’t own 12 Canon Speedlites). With the EL-1, 600EX-RT/600EX II-RT, and 430EX III-RT, which also have radio control in addition to optical transmission, you can control many more flash units optically, but only 15 radio-controlled Speedlites, in five different groups.
You can set up complicated portrait or location lighting configurations. Since the two top Canon Speedlites pump out a lot of light for a shoe-mount flash, a set of these units can give you near studio-quality lighting. Of course, the cost of these high-end Speedlites approaches or exceeds that of some studio monolights—but the Canon battery-powered units are more portable and don’t require an external AC or DC power source.
There are three key concepts you must understand before jumping into wireless flash photography: channels, groups, and flash ratios. Here is an explanation of each:
When using the EL-1, 600EX-RT, or 430EX III-RT in radio control mode, there are 15 different channels, plus an Auto setting that allows the flash to select a channel. In addition, you can assign a four-digit Wireless Radio ID that further differentiates the communications channel your flashes use.
The channel ability is important when you’re working around other photographers who are also using the same system. Photojournalists, including sports photographers, encounter this situation frequently. At any event populated by a sea of “white” lenses, you’ll often find photographers who are using Canon flash units triggered by Canon’s own optical or (now) radio control. Third-party triggers from PocketWizard or RadioPopper are also popular, but Canon’s technology remains a mainstay for many shooters.
Each photographer sets flash units to a different channel so as to not accidentally trigger other users’ strobes. (At big events with more than four photographers using Canon flash and optical transmission, you may need to negotiate.) I use this capability at workshops I conduct where we have two different setups. Photographers working with one setup use a different channel than those using the other setup and can work independently even though we’re at opposite ends of the same large room.
There is less chance of a channel conflict when working with radio control and all radio-compatible Canon flash units. With 15 channels to select from, and almost 10,000 wireless radio IDs to choose from, any overlap is unlikely. (It’s smart not to use a radio ID like 0000, 1111, 2222, etc., to avoid increasing the chances of conflicts. I use the last four digits of my mother-in-law’s Social Security Number.) Remember that you must use either all optical or all radio transmission for all your flash units; you can’t mix and match.
With the EL-1, 600EX-RT, 430EX III-RT, and ST-E3-RT, up to five groups (A, B, C, D, and E) can be used with as many as 15 different flash units. All the flashes in all the groups use the exact same channel and all respond to the same sender controller, but you can set the output levels of each group separately. So, Speedlites in Group A might serve as the main light, while Speedlites in Group B might be adjusted to produce less illumination and serve as a fill light. It’s convenient to be able to adjust the output of all the units within a given group simultaneously. This lets you create different styles of lighting for portraits and other shots.
TIP It’s often smart to assign flash units that will reside to the left of the camera to the A group, and flashes that will be placed to the right of the camera to the B group. It’s easier to adjust the comparative power ratios because you won’t have to stop and think where your groups are located. That’s because the adjustment controls in the menus are always arranged in the same A-B-C left-to-right alignment.
For example, if your A group is used as a main light on the left, and the B group as fill on the right, you intuitively know to specify more power to the A group, and less output to the B group. Reserve the C group (if used) to some other purpose, such as background or hair lights.
A particular Speedlite can have one of two functions. It can serve as a sender flash that’s capable of triggering other compatible Canon units that are on the same channel. Or, a Speedlite can be triggered wirelessly as a slave unit that’s activated by a sender, with full control over exposure through the camera’s eTTL flash system. The second function is easy: all current and many recent Canon shoe-mount flash, including the EL-1, 600EX-RT, 580EX II, 470EX AI, 430EX II, 430EX III, 430EX III-RT, EL-100, 320EX, and 270EX II can be triggered wirelessly. In addition, some Speedlites have the ability to serve as a sender flash.
I’m not going to discuss older flash units in this chapter; if you own one, particularly a non-Canon unit, it may or may not function as a receiver. For example, the early Speedlite 380EX lacked the wireless capabilities added with later models, such as the 420EX, 430EX, 430EX II, 430EX III, and 430EX III-RT.
Here’s a quick rundown of current flash capabilities:
You can use any combination of compatible flash units in your wireless setup. You can use an attached 600EX-RT/600EX II-RT, 580EX II, 430EX III-RT, EL-100, or ST-E2/ST-E3-RT as a sender, with any number of 600EX-RT, 580EX II, 470EX AI, 430EX III, 430EX III-RT, EL-100, 430EX II, 320EX, or 270EX II units (or older compatible Speedlites not discussed in this chapter) as wireless receivers. I’ll get you started assigning these flash to groups and channels later on.
The first step in working with wireless flash is to set up one unit (either a flash or controller) as the sender. You can mount a Speedlite EL-100, 580EX, 580EX II, EL-1, or 600EX-RT/600EX II-RT to your camera, which can serve as the sender unit, transmitting E-TTL II optical signals to one or more off-camera Speedlite receiver units. The sender unit can have its flash output set to “off” so that it controls the remote units with the pre-flash but omitting the main flash so the sender unit does not contribute any illumination of its own to the exposure. This is useful for images where you don’t want noticeable flash illumination coming in from the camera position. The next sections explain your options for setting up a sender unit for fully automatic, E-TTL II exposure. You can also use manual exposure instead of E-TTL II automatic exposure in wireless mode. Setting up your sender flash for manual operation is beyond the scope of this introductory wireless chapter.
Here are the steps to follow with the on-flash controls to set up and use compatible Speedlites as a camera-mounted sender unit for automatic exposure. (The EL-100 is set up as a sender using the Flash Function settings rather than controls on the flash; when you activate Wireless functions, Channel, Group, and Flash Ratio adjustments become available.) For each individual flash unit described below, check your flash’s manual if you have any questions about particular button location.
Canon’s Speedlite Transmitter (ST-E2) is mounted on the camera’s hot shoe and provides a way to control one or more Speedlites and/or units assigned to Groups A and B. The ST-E2 does not provide any flash output of its own and will not trigger units assigned to Group C. It has the following features and controls:
Here are the steps to follow to set up and use the ST-E2 transmitter (shown previously at left in Figure 10.2) as a camera-mounted sender unit:
The Speedlite EL-1 can serve as the sender unit when mounted to your camera, transmitting radio signals to one or more off-camera Speedlite EL-1, 430EX III-RT, or 600EX-RT/600EX II-RT receiver units. The sender unit can have its flash output set to “off” so that it controls the remote units without contributing any flash output of its own to the exposure. This is useful for images where you don’t want noticeable flash illumination coming in from the camera position. Just follow these steps:
The Speedlite 600EX-RT/600EX II-RT can serve as the sender unit when mounted to your camera, transmitting radio signals to one or more off-camera Speedlite 600EX-RT/600EX II-RT receiver units. The sender unit can have its flash output set to “off” so that it controls the remote units without contributing any flash output of its own to the exposure. This is useful for images where you don’t want noticeable flash illumination coming in from the camera position.
Here are the steps to follow to set up and use a Speedlite 600EX-RT/600EX II-RT as a camera-mounted sender unit for radio wireless E-TTL II operation.
The Speedlite 430EX III-RT can serve as a radio sender unit to trigger another 430EX III-RT or a 600EX-RT flash. Just follow these steps:
The ST-E3-RT transmitter can be mounted to the camera’s hot shoe and used as a sender controller to one or more receiver Speedlite 600EX-RT units. The ST-E3-RT and the 600EX-RT share essentially the same radio control capabilities except that the ST-E3-RT does not produce flash, provide AF-assist, or otherwise emit light and is therefore incapable of optical wireless transmission.
The layout of the ST-E3-RT’s control panel is virtually identical to the 600EX-RT. So is the menu system and operation, except that, as stated earlier, it will only operate as a radio wireless transmitter. Here are the steps to follow to set up and use the ST-E3-RT transmitter as a camera-mounted sender unit for radio wireless E-TTL II operation:
The ST-E3-RT controls receiver units as described earlier in the section, “Using the Speedlite 600EX-RT/600EX II-RT as Radio Sender.”
The whole point of working wirelessly is to have a sender flash/controller trigger and adjust one or more receiver flash units. So, once you’ve defined your sender flash, the next step is to switch your remaining Speedlites into receiver mode. That’s done differently with each particular Canon Speedlite.
In optical mode, Canon’s wireless flash system can work on any of four channels, so if more than one photographer is using the Canon system, each can set his gear to a different channel so they don’t accidentally trigger each other’s strobes. You need to be sure all of your gear is set to the same channel. Selecting a channel is done differently with each particular flash model. The EL-100 is the easiest in this regard: just slide the Receiver switch to the Channel you want to use.
The ability to operate flash units on a particular channel isn’t really important unless you’re shooting in an environment where other photographers are also using the Canon wireless flash system. If the system only offered one channel, then each photographer’s wireless flash controller would be firing every Canon flash set for wireless operation. By having four channels available, the photographers can coordinate their use to avoid that problem. Such situations are common at sporting events and other activities that draw a lot of shooters.
It’s always a good idea to double-check your flash units before you set them up to make sure they’re all set to the same channel, and this should also be one of your first troubleshooting questions if a flash doesn’t fire the first time you try to use it wirelessly.
You do this as follows:
With what you’ve already learned, you can shoot wirelessly using your camera’s on-camera flash and one or more external flash units. All these strobes will work together with the camera for automatic exposure using E-TTL II exposure mode. You can vary the power ratio between your on-camera flash and the external units. As you become more comfortable with wireless flash photography, you can even switch the individual external flash units into manual mode and adjust their lighting ratios manually.
But there’s a lot more you can do if you’ve splurged and own two or more compatible external flash units (some photographers I know own five or six Speedlite 580EX II or 600EX II-RT units). Canon wireless photography lets you collect individual strobes into groups and control all the Speedlites within a given group together. You can operate as few as two strobes in two groups or three strobes in three groups, while controlling more units if desired. You can also have them fire at equal output settings (A+B+C mode) versus using them at different power ratios (A:B or A:B C modes). Setting each group’s strobes to different power ratios gives you more control over lighting for portraiture and other uses.
This is one of the more powerful options of the EOS wireless flash system. I prefer to keep my Speed-lites set to different groups normally. I can always set the power ratio to 1:1 if I want to operate the flash units all at the same power. If I change my mind and need to make adjustments, I can just change the wireless flash controller and then manipulate the different groups’ output as desired.
Canon’s wireless flash system works with a number of Canon flashes and even some third-party units. I routinely mix a 600EX-RT, 600EX II-RT, 580EX II, 550EX, and 420EX. I control these flash units either with the on-camera external flash or using a Canon ST-E2 Speedlite Transmitter.
The ST-E2 is a hot-shoe mount device that offers wireless flash control for a wide variety of Canon wireless-flash-capable strobes and can even control flash units wirelessly for high-speed sync (HSS) photography. (HSS is described in Chapter 9.) The ST-E2 can only control two flash groups though.
Here’s how you set up groups (for flashes other than the EL-100, which has Group positions on its Mode Dial):
By default, all the flashes in each group will fire at full power. However, for more advanced lighting setups, you can select lighting ratios.
Your on-camera sender flash and your wireless receiver flash units have their own individual oomph—how much illumination they put out. This option lets you choose the relationship between these units, a power ratio between your on-camera flash and your wireless flash units—the relative strength of each. That ability can be especially useful if you want to use the on-camera flash for just a little fill light, while letting your off-camera units do the heavy work.
Having the ability to vary the power of each flash unit or group of flash units wirelessly gives you greater flexibility and control. Varying the light output of each flash unit makes it possible to create specific types of lighting (such as traditional portrait lighting, which frequently calls for a 3:1 lighting ratio between main light and fill light) or to use illumination to highlight one part of the photo while reducing contrast in another.
Lighting ratios determine the contrast between the main light (sometimes called a “key” light) and fill light. For portraiture, usually the main light is placed at a 45-degree angle to the subject (although there are some variations), with the fill-in light on the opposite side or closer to the camera position. Choosing the right lighting ratio can do a lot to create a particular look or mood. For instance, a 1:1 ratio produces what’s known as “flat” lighting. While this is good for copying or documentation, it’s not usually as interesting for portraiture. Instead, making the main light more powerful than the fill light creates interesting shadows for more dramatic images. (See Figure 10.4.)
By selecting the power ratio between the flash units, you can change the relative illumination between them. Figure 10.5 shows a series of four images with a single main flash located at a 45-degree angle off to the right and slightly behind the model. The on-camera flash at the camera provided illumination to fill in the shadows on the side of the face closest to the camera. The ratio between the two Speedlites flash was varied using 2:1 (upper left), 3:1 (upper right), 4:1 (lower left), and 5:1 (lower right) ratios.
Here’s how to set the lighting ratio between the sender flash and one additional external wireless flash unit:
Here’s how the various basic Group Configurations work:
Unfortunately, the R5 and R6 are not compatible with the optical mode of the Remote Release function found on certain Canon Speedlites, as the feature requires an infrared sensor remote control, which the mirrorless camera lacks. I’m mentioning this for owners of previous Canon models who have used this feature in the past with their Canon Speedlite 600EX-RT, 600EX II-RT, 430EX III, 320EX, 270EX II, or ST-E3-RT transmitter.
However, the EL-1, 600EX-RT/600EX II-RT, and ST-E3-RT transmitter do have their own remote release function, which allows you to use a receiver unit to trigger your camera by remote control when using radio transmission mode. EOS cameras released since 2012, including your camera, can be triggered in this way through the intelligent hot shoe, using an EL-1, 600EX-series flash, or ST-E3-RT transmitter mounted on the camera as a receiver, and the receiver EL-1 or 600EX-RT/600EX II-RT off camera as the remote trigger. Older cameras can still be used in this mode, but you’ll need to connect the on-camera “receiver” to the camera’s N3 three-pin remote control terminal using an optional Release Cable SR-N3. The remote release/linked shooting features operate within a perimeter of about 33 feet.
Check your transmitter/flash menu for a more complete explanation, but setup is relatively simple. The EL-1 allows you to choose REL (Release), located between the TEST and MODEL options in the bottom row of the flash’s LCD screen. On the 600EX-series, press the Menu 2 button on the unit which will be used as a remote/receiver flash and choose REL (release). Thereafter, a release signal is sent from the receiver to the sender/controller flash on the camera, and the camera will be triggered to take a picture and fire all the remote units. Remote release can be triggered only when autofocus can be achieved and is performed only using Single Shooting, regardless of the camera’s drive mode.
Linked shooting is also possible and allows triggering the shutter of a receiver unit camera by linking it to a sender unit camera. You can then trigger all the camera and flash units simultaneously. Each camera must have a flash that supports radio transmission wireless shooting, or you can use the ST-E3-RT transmitter on one or more of the receiver cameras. You’re better off using manual focus when triggering multiple cameras, because if even one camera is unable to achieve autofocus, linked shooting with that camera is disabled.
You’ll need to set the flash/transmitter on the sender camera as the sender of the multi-camera array, and the receiver flash/transmitters to linked receiver mode. On each receiver ST-E3-RT, you’ll need to press the Wireless/Linked Shooting button until Linked Shot appears. (The button is located on the left edge of the back panel, labeled with a double-headed lightning bolt icon, as shown earlier in Figure 10.2.) On the sender transmitter, press the button again to make it the sender. Note that each time you switch a unit from receiver to sender modes, any other units that had been set as “sender” will automatically switch to receiver mode. The Link light (at the top left of the back panel) of the receiver and sender units should be lit green.
Setting up the sender/receiver Speedlites is similar. The 600EX-series flash have their own Wireless/Linked Shooting button in roughly the same location on their back panels. Press that button and rotate the large Select Dial until Linked Shot appears, then press the Select/SET button. Use the control wheel to set each flash as Sender or Receiver, then press the Select/SET button.
Then press the button again to set the “sender” unit of the linked shooting configuration. When the Channel and ID are specified and ready, the Link lamp on the receiver unit(s) will illuminate in green. Then, point the remote/receiver flash used as a trigger at the front of the camera/sender flash within 16 feet of the camera, and press the remote control button on the side of the flash. During the two-second delay, you can then point the flash in a different direction (as is likely, because you’re probably using this feature to illuminate the scene, not the camera). That’s the real reason for the two-second delay, by the way: giving you the ability to reposition the “remote” release flash.