Just what we wanted for a long time. No IR transmission, but a reliable radio transmission with all the features you need. Controllable from the camera menu. A clean business. Total satisfied with the purchase. As you show the camera manufacturers, how it should look. Legal advised large, but so far 100% reliable. Update: I use the YN622C with the system flash 580 EX II. Otherwise, I have the Yongnuos with Metz 54 (SCA 3000) in all modes, including. ETTL used. Impeccable. The control of the camera's menu does not work here, but that's when mounted directly on flash this series also nich possible - you will reset all options on the flash unit. The transmission works but perfectly. Update2: YN622C-TX brought to - better it hardly goes. Also mixed operation with 580 EX II and Metz devices is as desired