im at the quest "discover the secrets of the Sierra Madre at the Vault's central chamber" i cant seem to pass these holograms and cannot find a blue alarm to shut down my collar from going off..i found a few pockets but the holograms see me in ever direction i need to go even with the assassin suit and stealth boy...anyone have any suggestions how i am supposed to pass this part of the level? HELP

Where exactly are you? At the three security guards by the forcefield in front of the door?

That was annoying, now that I'm remembering it. Getting down there and into that vault made me curse a lot. I can't remember if there are hologram emitters... but if there are, they are placed just like speakers: UP.

Look up, and also try looking behind you and up whenever you pass through a doorway. That's what worked for me (holy crap those speakers pissed me off something fierce in that place).

This may do it IIRC, keeping out of sight is key. There are three terminals that control the holographs and shield - the collar doesn't shut down, you just end up in safe areas between signals (there may be one). The terminal just before the holograph room (after water valve) lets you redirect the guard post for the first one - water valve. When redirected, follow it toward the force field and then duck in the room to the left. The first one will then turn and scan the area you were just in walking back and forth. Stay low at all times. Go to the next corner away from the main door, there is a holograph staring at you but you can trip the terminal and leave before it goes alarm condition. This is the tricky part due to both options for scan area were the same on my play through - just pick the second one. The second hologram guarding the door will now come to the terminal that you were just at. Run out the doorway toward the room on the far side (third terminal). Try to stay behind the holographs. You should be able to make it down the steps to the third terminal and redirect the last holograph and shut down the energy field. At this point run up and through the newly opened door to the main vault. Very hard to describe and will still take some trial and error, but this will get you off in the right direction.