User's Guide to the Hamilton Spectrograph

Table of Contents

Quick Reference
CCD Characteristics
Grating Tilt & Dewar Height
Filter Wheel & Shutter
Calibration Sources
Photon Integrator
Image Rotator
Iodine Cell & Slit Room Controller
Guide Camera & Filter Wheel
Data Taking System
Hamilton Motor Controller
Hamilton Focus
More Info:
Spectral Format
Navigating the Spectrum
Table of Orders
Setup Procedures
Observing Hints

Data Archive
Mt. Hamilton Homepage

Acquisition/Guide Camera

The camera is mounted near the spectrograph aperture plate, 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 hammotor_gui, 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.

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Last modified: Tue Feb 15 15:03:17 PST 2011