Procedure
https://docs.google.com/document/d/1S94E_sG0lsHjCt70gnzeCo6ReKtVgDCiAdlnnkhN10c/edit
HeNe (greeny) mirror in/out:
Align the laser vector
Alignment procedure:
- downstream camera: DSOTR → channel 3/4
- upstream camera: Frontview (normally), IPOTR1 (if frontview doesn't work) → channel 1/2