CCD Camera and Motorized Wheels
An intensified CCD camera is used for acquiring and centering objects.
There are four motorized wheels in the photometer: a filter wheel, an
aperture wheel, an optics turret, and an ND filter wheel in front of the
camera to protect it and extend its dynamic range to brighter objects.
Light entering the photometer first encounters the
aperture wheels, then
the 4-position optics turret where the light is directed as follows:
a wide-field mode where the camera can see a field about an inch across
at the focal plane; a narrow-field mode so the camera can work with the
smaller apertures; an eyepiece mode for viewing directly by eye instead of
using the camera; and an open hole for light to reach the filter wheel and the PMT
detector.
The camera (and the eyepiece) are located behind the aperture wheel for
centering an object in the aperture. For additional information not
included here, use this contact list.