Sheila, Kiwamu, 

Today we realized that the centering on MC3 that we did on friday night resulted in a bad mode cleaner alingment.  We used DOF 4 to minimize the angle to length coupling of MC3, but this resulted in operating close to the edge of the osem range.  While Kiwamu and I were trying to align IM1+IM2 to get through the faradat this afternoon, the mode cleaner got into a state where MC3 was constantly tripping.  We plan to go back to the mode cleaner alignment as of friday afternoon, live with the clipping in the IM1 trans path and move on to aligning the IMs and PRM tomorow.  

The good news is: we know how to look through the veiwport and align the beams through the Faraday, and IM1+IM2 give us plenty of actuation range to do this.  

Our mistakes were:

The beams on the wall are IM4 trans, not IM2 trans.  The rumor I started that they were IM2 trans caused us to think we didn't have enough range on IM1 on friday, which is why we started the centering on MC3 in the first place. 

We centered on MC3 by introducing an offset to DOF4, which changes more than just the centering on MC3.  

We might want to measure the spot positions on all 3 MC mirrors and compare to Jax's measurement in alog 6676, to see if this makes sense. 

Just to note: on saturday Stefan and I realigned the IM1 trans path on IOT2L, when we revert the MC to friday afternoon we will have to realign that.  This afternoon I restored the PZT to where it was friday afternoon, and restored MC1 to where it was friday afternoon using the witness sensors.  After that we realigned the refl path on IOT2L roughly.  The next steps are to restore MC2+3 using the witness sensors, and fine tune the alignment on the refl WFS once the MC is locked.