Hi i have a yongnuo yn568ex11 flash and it says on the box wireless bought a yn622ctx trigger to go on the camera to fire the off camera flash but i cant get it to work does anyone know why thanks
Your YN622C-TX will trigger a YN-568EX II only if there is a YN622C/YN622C II receiver attached to the flash. Of course you also need to be sure the TX and the receiver on the flash are set to the same channel.
The YN622C-TX is a radio transmitter.
The wireless receiver built into the YN-568EX II is an optical receiver.
To trigger the YN-568EX II without an additional trigger attached to it you need a flash or optical controller such as another Canon Master Flash (YN-568EX II, Canon 580EX, Canon ST-E2, etc).