I recently bought a new YN-560 II hotshoe flash but found that it has neither TTL nor assist beam for focusing in low light situations.
The problem now is that I'm starting my career as a night photographer (usually night clubs and concerts and so on, where everything is constantly moving) and my Canon 650D can't focus at all when the YN-560 II is attached to the hotshoe mount. Further, there is no assist beam in my flash unit and the camera's assist beam is disabled when the external flash is attached.
The question now is, how can I achieve auto focusing in these low light situations? Is buying a new flash with TTL & assist beam a must? Or is there a way to force camera's assist beam into being enabled even when the YN-560 II is attached?