Rudy Winston
Rudy Winston

Rudy Winston has over 16 years experience with Canon USA's Pro Products team, and has been responsible during that time for training Canon's staff on new products, creating presentations for customers and dealers, numerous writing projects, and providing technical assistance to professional and amateur photographers.

Remote camera firing with the Speedlite 600EX-RT and Speedlite Transmitter ST-E3-RT

August 02, 2013

Many Canon users aren’t fully aware that the Speedlite 600EX-RT and Speedlite Transmitter ST-E3-RT can actually be used as a remote control device to trigger one or more cameras. With their new radio transmission technology, each has two distinct methods to allow an off-camera Speedlite or Transmitter to fire between one to 15 compatible Canon EOS cameras. We’ll discuss these two methods in this article, and provide some examples of when one or the other might be a useful feature to try.

The Remote Release and Linked Shooting are above and beyond the remarkable ability of the new Canon radio Speedlite system to provide full control of up to 15 “slave units” off-camera for wireless E-TTL or manual flash. Please note that these two functions are exclusive to Canon’s new radio system and are not compatible with traditional “optical” wireless flash technology or equipment.

Remote Release: firing an EOS camera using an ST-E3-RT or 600EX-RT

Remote Release is a feature built into both the Speedlite 600EX-RT and the optional Speedlite Transmitter ST-E3-RT. Simply stated, if you have one compatible EOS camera with either device mounted, you can take another 600EX-RT “slave unit” off-camera and fire the camera by pressing a single button on the flash in your hand. The off-camera Speedlite communicates to the on-camera unit and triggers the camera to fire.

Remote Release offers some intriguing possibilities for EOS users who have invested in the Speedlite 600EX-RT system:

  • Remote camera control when using wireless flash from up to 100 feet away
    Press the “REL” (release) button on any off-camera Speedlite 600EX-RT slave unit in a wireless flash set-up and fire the camera and all flashes in your set-up. You can be as far as 100 feet (30m) from the camera, in any direction.
  • Have an on-camera Speedlite 600EX-RT fire or not fire during actual exposure
    When triggering a camera with a Speedlite 600EX-RT mounted, all Speedlites in a radio-based wireless set-up will fire. But you have the choice of whether the on-camera “master unit” fires or not. To set this up, go to Menu 2 of the master unit and press the far left control button to activate Master Flash Off. The three small “rays” of light from the Speedlite icon on the back of the master unit disappear, telling you the on-camera flash will act as a master, but won’t fire during final exposure.
  • Use a single Speedlite 600EX-RT “slave unit” off-camera, without flash appearing in an image

    This requires a bit of a work-around because, by default, a slave unit will fire during exposure when it’s used for Remote Release. But doing so will allow you to use a Speedlite as a remote triggering device in an available light set-up.

    If using a Speedlite Transmitter ST-E3-RT on-camera as the master unit, there won’t be any flash from camera position (with a Speedlite 600EX-RT on-camera, to prevent flash firing, set Master Flash Off as described immediately above). But you can at least partially get around the off-camera slave unit firing in your hand by setting the master unit (on-camera) to Manual flash mode, setting wireless radio control on the master unit to “ALL” and adjusting its power level to its minimum 1/128 power level setting. This way, the off-camera flash fires at its weakest power level. Furthermore, the flash head can be turned away from the scene or even covered during exposure; radio transmission still occurs normally (unlike with previous “optical” wireless flash systems).

Linked Shooting: fire up to 15 cameras, using radio transmission

Linked Shooting is the second remote, radio-based method of firing cameras. Linked Shooting differs from the Remote Release system in three fundamental ways:

  1. Anywhere from one to 15 cameras can be triggered remotely with Linked Shooting (Remote Release can only fire one camera).
  2. Wireless multiple off-camera flash is not possible in Linked Shooting (this is a significant difference compared to Remote Release).
  3. Linked Shooting can be activated either by pressing the “REL” button on an off-camera Speedlite ST-E3-RT or 600EX-RT set to “Linked Shot/Master” or by attaching either to a compatible EOS camera, again setting the device to “Linked Shot/Master” mode and then firing that camera normally. Up to 15 additional “slave” cameras can be simultaneously triggered by either method.

With Linked Shooting, each remote camera to be fired must have either a Speedlite 600EX-RT mounted on it or a Speedlite Transmitter ST-E3-RT. These devices must be pre-set to Linked Shot/Slave mode (instructions are listed below).

Nature, event, macro, editorial, sports shooters and more can set-up multiple EOS cameras, aim them from up to 100 feet away and fire them together with a Speedlite or Transmitter held in their hand. Photojournalists can likewise ensure the same subject is captured from multiple camera angles, if remote cameras can be positioned ahead of time at a major news event.

Before going any further, let’s be absolutely clear: when two or more EOS cameras are triggered via Linked Shooting, it’s not possible to guarantee exact shutter synchronization among the cameras. In other words, they may not all fire at the same split-second because the same shutter timing can’t be assured. Therefore, multiple flash shooting is disabled in Linked Shot mode with Speedlites. We recommend against trying studio flashes or third-party devices to fire one set of flashes and have them expose at the same time for multiple cameras.

But for available light shots with multiple cameras or when using a single flash on each camera for main or fill-in lighting, Linked Shooting offers some excellent potential. Without having to invest in additional remote control devices, a Canon shooter with radio-based wireless Speedlite gear has in his or her hands the devices they need for simultaneously firing multiple cameras remotely.

Set-up for Remote Release

For the Remote Release function, you need an off-camera Speedlite 600EX-RT, set as a radio-controlled slave unit. And on the remote camera, you need either a Speedlite Transmitter ST-E3-RT or another 600EX-RT flash as a radio-based “master unit.” Note that for Remote Release, a Speedlite Transmitter ST-E3-RT cannot be used as the off-camera triggering device because it doesn’t have a slave mode.

Up to 14 additional Speedlite 600EX-RT units can be used off-camera for multiple wireless flash, if desired. Pressing the “REL” button on the back of any of these slave units (set to display Menu 2 on the flash unit’s LCD panel) will trigger the camera to shoot as well as fire all off-camera slave units.

There is no built-in system to completely disable the slave unit being used for Remote Release from firing, although a couple of possible workarounds were described above. Again, if a Speedlite 600EX-RT is mounted on-camera as a “master unit,” it can be instructed not to fire by setting it to Master Flash Off on Menu 2 of the master’s LCD panel or on the camera’s External Speedlite Control menu:

Shooting Menu > External Speedlite Control > Flash function settings > Master Flash firing > Enable / Disable

The Remote Release option is clearly the method of choice for any EOS shooter who wants to use multiple wireless Speedlites, and trigger a single camera in the same set-up remotely.

Set-up for Linked Shooting

Linked Shot mode is a separate control method and unlike the Remote Release method, it does require that both the triggering device and each on-camera receiving unit be pre-set into a special Linked Shot mode -- we’ll describe that momentarily. Once again, with Linked Shooting, up to 15 EOS cameras can fire together, triggered by pressing the shutter button on one camera with a Speedlite or Transmitter mounted and set to Linked Shot/Master mode or by a button press on a hand-held, off-camera ST-E3-RT or Speedlite 600EX-RT.

Each camera in a Linked Shot set-up must have either an ST-E3-RT or Speedlite 600EX-RT mounted. Camera compatibility will be discussed shortly.

On-camera device

This would be for pressing the shutter button on one EOS camera, while simultaneously triggering up to 15 additional cameras within 100 feet (30m) of the “master” camera.

For Linked Shooting, either a Speedlite 600EX-RT or Speedlite Transmitter ST-E3-RT must be mounted to a compatible EOS camera. Any combination of Speedlites and/or Transmitters can be mounted to other cameras to be fired.

  • Speedlite 600EX-RT

    Press the Wireless Button (with lightning bolt icon) on rear of flash repeatedly until flash is set for normal, on-camera operation. In other words, no wireless icon at all appears on the upper-right corner of a Speedlite’s LCD panel. Be sure it’s not set for radio-based wireless in this step!

    Now press and hold in same Wireless Button for about two seconds, until “Linked Shot” appears on LCD panel.

    Quickly tap the Wireless Button again to toggle between Linked Shot “master” and “slave” mode. For use on a camera that’s going to be fired and then trigger other cameras, set it to Linked Shot/Master.

  • Speedlite Transmitter ST-E3-RT

    Press and hold down the Wireless Button (lightning bolt icon on the button) for about two seconds until “Linked Shot” appears on the transmitter’s LCD panel.

    Quickly tap the Wireless Button again to move from “slave” to “master” Linked Shot operation. Again, be sure it’s set to Linked Shot/Master for use on a camera that you’ll be firing to trigger other remote cameras. If you press it twice and the transmitter goes back to the radio wireless mode (Linked Shot no longer appears), let go of the button and then press and hold it in for another two seconds to re-enter Linked Shot mode.

Off-camera triggering device

Turn either a Speedlite 600EX-RT or Speedlite Transmitter ST-E3-RT on and then carry out the same steps outlined above to turn it into a hand-held device you can use to trigger for one to 15 remote EOS cameras.

Remote EOS cameras

Each “slave camera” must have an attached Speedlite 600EX-RT or Speedlite Transmitter ST-E3-RT (any combination of these two devices, up to 15 total units, is okay). Follow the steps above, but be sure to set each one to “Linked Shot/Slave” mode.

Flash with Linked Shot mode — yes or no?

Any of the cameras with a Speedlite 600EX-RT mounted won’t fire the flash during exposure at the factory default settings in Linked Shooting mode. To enable flash firing from either the master unit or any of the remote slave cameras, go into that flash unit’s Personal Functions, scroll to Personal Function 07 and set it to option “1” (Linked Shot – ENABLE).

It’s possible for a master camera’s flash not to fire and the 600EX-RT on one or more slave units to fire during exposure. To resolve this, set each independently as described above. Note that while flash Custom Functions can be set on newer EOS cameras using the camera’s External Speedlite Control menu, the Personal Functions of the 600EX-RT must be set on each flash unit’s LCD panel.

Again, flash operation in Linked Shooting mode is limited to flash on-camera only. A multi-flash, wireless E-TTL set-up is only possible with the Remote Release function and cannot be done in Linked Shot mode.

Compatible cameras for remote firing

Canon EOS SLRs introduced in 2012 or later have revisions to their design that allows a connected Speedlite Transmitter ST-E3-RT or 600EX-RT flash to receive a radio signal and fire the camera directly through the contacts on the camera’s hot shoe. Thus, all that’s necessary for Remote Release or Linked Shot mode is to have either device mounted on the camera’s accessory shoe, set it appropriately and you’re good to go.

Here are the cameras that require no extra cords for these types of remote shooting:

  • EOS-1D X
  • EOS 5D Mark III
  • EOS 6D
  • EOS 70D
  • EOS Rebel T4i, T5i, SL1 and later models
Other EOS cameras

For models introduced before the launch of the Speedlite 600EX-RT, such as the EOS 7D, 5D Mark II and so on, you’ll need to connect the optional Canon Speedlite Release Cable SR-N3. One end of the SR-N3 cord plugs into a single-pin socket on the upper-left side of the 600EX-RT or ST-E3-RT. The opposite end is a standard 3-pin “N3” type remote control connector, which plugs into the remote control socket of mid-range and high-end EOS SLR cameras.

Please note that all EOS Rebel models to date, as well as the EOS 60D, use a different single-pin remote control socket on the camera body and are not compatible with the SR-N3 cord. Because Canon doesn’t (as of mid-2013) market a compatible adapter or connecting cord this means that Remote Release and Linked Shooting are not compatible with these cameras, unfortunately. However, any older EOS SLR model with the 3-pin “N3” remote control socket can use the new radio-controlled Speedlite system for either remote firing method, via the optional SR-N3 cord.


While Canon EOS users have always been able to connect a remote control cord and fire a camera, the convenience of truly wireless remote firing hasn’t been as easy. Now, Canon has leveraged the radio technology in its Speedlite 600EX-RT system to not only revolutionize how photographers can shoot with off-camera flash, but use these same flashes as remote controllers to actually fire one or more EOS cameras.

Remote Release and Linked Shooting open some very useful potential to the serious EOS user. The ability to trigger cameras up to 100 feet or more away makes it easier than ever to accomplish anything from reducing camera vibration in a macro shot to positioning up to 15 cameras in a 360° arc around a subject and firing them at the same time.

Once a user has a clear picture of how the Remote Release and Linked Shooting modes differ and how they each can be applied, they can begin to look into the possibilities and expand on the images they are able to create.

The CDLC contributors are compensated spokespersons and actual users of the Canon products that they promote.

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