# Adjust the acquisition camera focus in the bottom right ''Camera Focus'' box until the scratches on the slit jaw appear as sharp as you can get them.
==Recipe for setting Setting up the slit position on the TCS - using the SpUpNIC Control GUI==
The purpose of this step is to figure out where on the acquisition image you need to place your star, in order for it to land pretty close to the ideal spot on the slit. Very bright stars can be seen reflected on the slit jaws, and can be placed on the slit directly, but this is not the case for fainter stars, which need the superior reflectivity of the guide mirror in order to be seen on the acquisition camera.
# Move the guide mirror into the beam, either by setting the "''Acquisition" '' state in the "''Lamp/Mirror Settings" section '' pane of the SpUpNic SpUpNIC control GUI (if it says Guide Mirror "''Science"'', click "''Change"''), or by clicking on the guide mirror in the graphical viewinstrument schematic.
# Acquire a bright star (e.g. ~4 mag from the Bright Stars chapter of the Sutherland Almanac, available in the warm room), roughly centre it on the acquisition camera and continue exposing.
# Move the guide mirror out of the beam.
# Move the rear-of-slit mirror into the beam ("''Lamp/Mirror Settings" section'' pane, "RoS mirror" change from "''Out of beam" '' to "''In beam"'').# Turn on the slit illumination (in the "Instrument Setup" move the Slit illumination slider to .... and click pane, "Change" to turn on the lamp). Tune the exposure time/LUT sliders on the TCS until you can clearly see the slit running horizontally across the acquisition image, approximately halfway up.
# Using the hand paddle, move the telescope to place the star on the slit, approximately one third of the image width away from the right-hand edge.
# Turn off slit illumination.
* ssh -Y tcs@172.17.1.224
* password ******* (you should have been supplied with the password)
* sudo ./1X1_thread_forms-depth 24
* password *******
# .....description of pottercam when functioning sensibly.......
# An image window for the rear-of-slit camera will pop up. This looks up at the slit from behind, to enable you to check that your star is centred on the slit. Move the telescope such that the star falls on the centre of the slit image in both x and y.
# Move the rear of slit mirror out of the beam and take a test spectrum (e.g. 20 seconds) of the bright star (in "the ''Exposure/CCD info" '' pane, select "''Exposure type" "Science" '' = SCIENCE from the dropdown drop-down menu, enter "''20" '' in "''Exposure time" '' and click "''Expose"'').
# The resulting image will be displayed on Monitor 2. You are aiming for the spectrum to fall on approximately the central row of pixels. If the spectrum is too high, move the telescope slightly ...east?west? ; if too low, move the telescope slightly west/east.....? ?
# When you are happy with the position of the spectrum on the image, on the TCS, add a red marker over the position of the star on the slit (TCS "Pointer" pane: "Markers", "Add a red marker").
# Finally, move the guide mirror into the beam, and add a second red marker at the position of the star. This marker will be used to approximately position stars on the slit that are too faint to be seen reflected off the slit jaws.