User's Guide to the Shane 3-m Telescope

Table of Contents

Diagonal Mirror
TUB Rotation
Arc & Flat-field Lamps
trouble report
Remote Operations
Mt. Hamilton Homepage

Arc & Flat-field Lamps

Flat-field lamps are mounted on the top of the secondary mirror support. For light from the flat-field lamps to reach the instrument, the primary mirror cover must be open and the diagonal mirror should be in position 1 or 3 (or 4 if using the Kast Spectrograph).

Several arc spectrum lamps are mounted in the TUB for calibrations. For light from the arc lamps to enter the instrument the diagonal mirror must be in position 2, so that the white card on the back of the diagonal mirror reflects light into the instrument. The slinelamp_fe program allows the lamps to be controlled remotely. This program also controls the flat-field lamps mounted on the top of the telescope.


The arc and flat-field calibration lamps are both controlled from the slinelamp_fe user interface. slinelamp_fe is started by typing slinelamp_fe on either gouda or karnak computers.

The top portion of the GUI controls the arc lamps and the bottom portion the flat-field lamps. Clicking on the "Expand >>" button will bring up a list of available lamps with buttons for turning them on or off.

The lamps are on timers so they will turn themselves off after 30 minutes, unless the timer is reset or a different time span is selected via the "Timer is On" button. "Time Out" is the length of time, in minutes, for which the timer is currently set. "Time Left" is the amount of time left, in minutes, before the lamps are turned off. Please turn off lamps when not in use, as the lifetimes of the arc lamps tend to be short and replacement lamps expensive.

Status messages for the lamps and controller are displayed in the upper portion of the arc or flat-field lamp GUI section.

Figure 1: slinelamp_fe GUI

When the GUI is expanded, the names of the available lamps are displayed. Clicking the name of the lamp will bring up a menu allowing you to turn on or off the lamp, or turn off all lamps (with the exception of the Super-Blue dimmer).

You can define up to two groups or "blocks" of lamps (see Figure 2) to be turned on/off via the "Block is Inactive"/"Block is Active" buttons. These buttons are available when the GUI is "Collapsed", saving screen space for other or more important user interfaces. This is particularly convenient for the arc lamps where multiple different lamps are desirable for wavelength calibrations on the Kast spectrograph red and blue sides.

There are currently three flat-field lamps available: Blue, Red, and Super-Blue. All three are mounted on the Cassegrain secondary mirror housing.

  • The Red lamp is rather dim and red, suitable for wide or intermediate band direct imaging flats.
  • The Blue lamp is much brighter and better suited for dispersed or narrow band direct imaging flat-fields.
  • The Super-Blue lamp is a flat-field lamp whose brightness is controlled through a rheostat. To turn on the lamp, type in the desired dimmer setting (range is 0 to 100; 0 being off and 100 full brightness) and click the "Set" button. Click the "Off" button to turn the lamp off.

Figure 2: Expanded slinelamp_fe GUI

The Functions menu allows access to diagnostic information from the lamp controller as well as the message log window. It also gives you access to the "Exit" command to exit the GUI.

Figure 3: slinelamp_fe Functions Menu

Last modified: Thu Mar 4 12:29:25 PST 2010