Install shutter (P-200 only)

 If the Fabry-Perot is being used on the 200-inch telescope with the F/9 guider base, the shutter internal to the instrument should be used. This is due to a conflict between the solenoid of the shutter in the F/9 guider base and the oversize 3-inch filter holders that have been developed in order to allow use of the narrow-band filter set from the 60-inch telescope. As mentioned in the previous section, the user should note on their green sheet that the shutter in the F/9 guider base should be removed prior to the installation of the base.

The internal Fabry-Perot shutter fastens to the back side of the camera lens plate and should therefore be installed before mounting the camera lens. To install the shutter, place it in the recessed square region on the back of the camera plate. The shutter solenoid should protrude through the rectangular hole in the camera plate. Since the shutter will be pinched between the camera and dewar plates, it should be sufficient to secure the shutter with a few pieces of tape. Be sure not to get tape over the shutter or around the edge of the camera plate, in order to ensure a light-tight mating with the dewar plate. After installation, the shutter should not interfere with the ability of the dewar plate to lie flush against the camera lens plate. You may want to place black tape around the shutter solenoid to remove possible light leaks.