The camera is mounted near the spectrograph
, where the
latter's mirrored surface reflects the telescope beam to the camera via
an intermediate turning mirror. Operation of the camera and guider are
covered in the CAT Users' Manual
(when observing with the 3-m, the telescope operator runs the
camera and autoguider) and in the
Lick Autoguider Manual
Though the acquisition/guide TV is more properly regarded as a telescope
system than as part of the spectrograph, its magnification
and focus are controlled via the
, the spectrograph control interface.
Using the TV system is covered under
acquisition and guiding
The camera assembly can be moved towards or away from the
entrance slit to change magnification. The camera can either be in the
full-forward position for high magnification, or fully backed out for
low, but cannot assume an intermediate position. The camera lens must also
be well-focused on the aperture plate for observing.
A 4-position filter wheel (shown below) lies just in front of the camera lens.
It is remotely operated from push-button panels in the 3-m or CAT control
rooms. A toggle switch on each panel selects between control rooms. The filter
wheel accepts 2x2-inch filters in standard Lick filter holders. Neutral density
filters are used to dim very bright stars; color filters may be used at
large hour angles to limit the effects of atmospheric refraction on guiding.
Last modified: Tue Feb 15 15:03:17 PST 2011