With the image slicer it is vital that LAMBDA offsets be used, by
issuing the LAMBDA command to the telescope computer control system (CCS).
This takes a few seconds to move the star; be patient. The LAMBDA correction
should be revised at the end of each exposure by setting LAMBDA 5500 Å ,
recentering the star on the slicer aperture, and then issuing LAMBDA 
again.
TV guiding is straightforward. Use the CCS TVCR command. The SS1 and SS2 lights should be off and the SS3 light on.