Problem karlsuss SNF 2010-04-21 14:39:35: cannot focus on both wafer and mask at 20x

[tdo at snf.stanford.edu]

cannot focus on both wafer and mask at 20x with enough clarity to do a 2um alignment.  tried different wafers and removing/cleaning/replacing mask.  had problem with both left and right objectives.  switched to karlsuss2 and it was much better