I've just got my hands on the brilliant 5D Mark IV and understood that it had a built in wireless flash trigger. I was hoping this might link to my Speedlite 430EX III-RT and allow me to use my (single) flash wirelessly off-camera, without having to buy a radio transmitter or additional wireless flash.

I've tried to set this up, but the link indicator on the flash is showing red (not connected) and I'm not sure if the camera is really capable of this mode of operation.

Would appreciate your guidance.

  • Where in the world did you get the idea that the 5D Mark IV has a built-in wireless flash controller?
    – Michael C
    Nov 11 '16 at 13:08

The specs do include Radio transmission wireless flash shooting among the features, so I can see how you got that impression. But they also list Optical transmission wireless flash shooting despite the fact that the 5DmkIV doesn't have the built-in flash that would be necessary for optically triggering an off-camera Speedlite. I can see how it might be confusing that they list both those features even though the optical and radio triggers aren't built in, but notice that they're listed under the heading External Flash Settings; like other recent EOS bodies, the 5DmkIV can control many of the settings of compatible flash units through the camera's menu system, including which trigger system you want to use.

Just as you need to connect a Speedlight that can work as an master unit to trigger other units with Canon's optical system, you also need a radio-capable master unit connected to the camera to trigger other units using the radio system.


The Canon EOS 5D Mark IV has a built-in Wi-Fi radio with NFC (Near Field Communication) capability. It does not feature a built in radio transmitter for communicating with RT flashes.

You'll need either a Canon ST-E3-RT or Yongnuo YN-E3-RT to control off-camera RT flashes using wireless radio. You could also use a wireless optical controller such as a Canon or Yongnuo ST-E2 or an optical master flash such as the 90EX.

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