Changes
/* Focusing the spectrograph */
# On completion of the sequence: in the SpUpNIC Quick-Look GUI, in the log box to the left of the spectrum display window, you will see a list of focus positions and their corresponding pixel shifts. Best focus corresponds to a shift of zero.
# Enter the best focus into the ''Requested Camera Focus'' box on the SpUpNIC Control GUI's ''Instrument Setup'' pane and click ''Go''.
# The Hartmann sequence ends with the shutter out of the beam, but for some reason it sends the slit width to zero! So select the desired slit width in the ''Instrument Setup'' pane and click ''Go''. Check that it goes to the required position, click ''Go'' again if it does not do it the first time.
# Select "Exposure type" = ARC and take an arc to confirm that the focus looks good.
# Click on the arc mirror in the schematic to switch off the arc lamp and move the arc mirror out of the beam.
