playerxplayer c-hing, if you would like to join the photo event, yes, you should first buy the ticket of the show (through the ticket office in the theatre or through the travel agents' offices in the ferry terminal)
then you should line up outside the entrance of the theatre before 2:00pm, from our experiences, there would be staffs from Rockza telling you what to do
the duration of the photo event varies depending on how many people attending
the more people attend, the longer time it would take
please note that according to Rockza manager, the photo event would be
FIRST COME FIRST SERVE
so if you don't want to miss the chance of getting "close" with the performers, you should come a bit earlier
Rockza's staffs would provide camera for us