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Next Page: Spectrograph focus; adjusting the CCD camera
If an object is visible on the coarse autoguider fibre, then using the
TCS handset to offset in the 
Y direction should move the image
towards the top right of the CCD, and offsetting in the X direction
should move the image towards the bottom right of the CCD; the angle
between the autoguider CCD y axis and the TCS handset Y axis is
approximately 70 degrees.
If this has changed, it will be necessary to use GSEXAM to modify the TCS variable GUI_GD_ROTATION(3), otherwise the loop cannot be locked. This is the rotation angle of the autoguider CCD in radians, currently set to 1.213 radians (about 70 degrees). Once this has been set correctly, and the autoguider loop succesfully closed, have the constant GUI_GD_ROTATION(GUI_K_UESCOARSE) in the WHT.INI startup file modified and do a slow startup of the TCS.