Starting the guider camera

 Before starting your observations, it is useful to verify the operation of the guider camera. The guider systems on the 60-inch and 200-inch telescopes are quite different:

• 60-inch
  The primary issue concerning the guider system on the 60-inch telescope is to verify that it can be focused at the current telescope focus. A new guider camera system was installed in November, 1998 which initially could not be focussed simultaneously with the Fabry-Perot instrument. If this condition remains at the time of your run, be assured that the guider system can function with unfocussed stellar images (i.e., doughnuts), provided that a sufficiently bright star can be located.

  The guider camera should now be focused, preferably right after the telescope is focused. The observing assistant will be able to help with this. If the camera does not focus in the allowable range on the 60-inch telescope, simply adjust it to the best focus possible.

• 200-inch
  The primary issue concerning the guider system at the 200-inch telescope is to determine the acceptable range of movement of the camera arm. The guider system in the F/9 guider base uses a mirror on the end of a pivoting arm, which can be swept across a significant portion of the telescope beam. However, the path of the guider arm includes the actual CCD field of view, meaning that the guider arm may be positioned such that it occults the CCD. Clearly, this is an undesirable situation.

  To determine a reasonable range of movement for the guider arm, first move the guider arm to its home position:

  
  
  
  Then remove the filter, turn on a source of illumination, such as the flat lamp, and take an image:
  
  
  
  You should see very little illumination, if any, as the guider camera arm will occult the CCD field of view in its home position. (This can be verified visually, if you are performing this step without the Fabry-Perot mounted.) To determine a minimum value for the camera arm position which will not occult the CCD, repeatedly increment the camera position and take additional exposures:
  
  
  
  Note that the positional units for the guider camera arm are quite small; the total range is approximately 500,000. Note also that the f9tvmove command performs relative moves only; you may use the f9tvstat command to determine the current location of the guider camera relative to the home position. Be sure not to move too close to the home position, or the guider camera arm will occult the field of view.