Canon WFT-E7 Instruction Manual page 77

Do not use multiple flash units. Although slight, there is a difference in

the shutter release timing which may cause out-of-sync flash firing and
inadequate exposure.
Linked shooting is not possible when sender and reciever cameras are

set to [Mirror lockup] [Enable] or [Enable:Mirror down w/ s].
During linked shooting, when you press the AE lock or depth-of-field

preview button, the camera adjusts the focus and meters as if you had
pressed the shutter button halfway.
Once you have established a connection between the sender camera

and reciever cameras, the settings are retained even after you replace
the batteries.
If you will no longer use a reciever camera in linked shooting, set

[Communication mode] to [Disconnect] on that reciever camera.
Any cameras compatible with linked shooting, when they have WFT

series transmitters attached, can be used as reciever cameras,
regardless of model.
Positioning the Cameras
77