off camera flash – How to control a Canon 430ex ii from a YN-622C-TX?

Take the 430EXII out of slave mode. That’s for Canon’s optical wireless system, and is basically telling the 430EXII not to listen to the signals on the foot pins, but to the red sensor panel on the front instead. And your YN-622C is sending signals via the foot pins.

The 622 radio slaving is separate and a different system than the built-in Canon wireless eTTL system. Your camera’s menus can do both, so this is where the confusion comes in.

The YN-622 system is basically just bridging the hotshoe/foot communication over radio, like a radio eTTL cable. So, your flash needs to be set as if it’s on the hotshoe, and you command the flash from the camera menus as if it’s on the hotshoe.

See also: the “Getting Started” section of Clive Bolton’s The Other YN-622C User Guide.