where is "3rd party flash in LV"?

[gkase]

Hello...
I am trying to get my 550D to fire external, non-canon, studio strobe units. I am given to understand there is a feature called
"3rd party flash in LV"  or something like that...can anyone help me find this in the menus? My goal is to be able to frame and focus in live view and hit the shutter button to take a flash image using external strobes.
thanks
George

[gkase]

Never mind...I knew I had the latest version of ML but I was using another SD card with version prior to having this feature...
no wonder it was not findable...for future seekers...you can indeed shoot an external studio strobe setup with a T2i or 550d. just go under the "Shoot" menu and you will find the 3rd party flash toggle. It temporarily disables the live view, shoots with flash trigger and then returns to live view. works great and many thanks to Alex or whoever did the tweak.
George