We have a nifty little blog post here with the basics!

No. Due to changes in Canon’s implementation of the E-TTL II flash protocol, the FlexTT5 for Canon does not work with the latest generation cameras and flashes such as the 5D Mark IV and Speedlite 600EX II-RT.

If you’re using the latest and greatest Canon gear, you’ll want at least one FlexTT6 for Canon to be used as the primary on-camera transmitter. All other receiving units down the line can be FlexTT5, regardless of camera or flashes used.

The FlexTT5 works with both the PocketWizard Plus III and Plus X models; however, the FlexTT5 may need to be synced to these units in order to function. To sync the FlexTT5 to another FlexTT5, a Plus III, or a Plus X unit, simply press and hold the TEST/LEARN button on the receiving unit until it glows a solid amber. While the receiver is doing this, press and hold the TEST button on the transmitting unit for a few seconds. This should sync the two units together.

The FlexTT5 has had a lot of problems with very short transceiver range. They sometimes lose signal from only a few feet away. If you need a more reliable unit, we recommend staying with the standard PocketWizards. They don’t do TTL, but they always work.

This rental includes a single FlexTT5 unit. You’ll need to rent a separate FlexTT5 or other PocketWizard unit to act as a receiver.