In this capacity, an aperture mask wheel is located directly at the focal plane of the prime focus, while reimaging optics, a grism wheel, and the CCD are mounted in a pedestal above the focal plane. In this mode, imaging, longslit spectroscopy, and multislit spectroscopy are available. There is some significant vignetting for the imaging which increases rapidly towards the corners of the available field-of-view. There are currently metal and photographic emulsion longslits available of various sizes. Multislit aperture masks are created by the user in advance of the run using a procedure described elsewhere in this manual, resulting in a photographic emulsion which is the mask. The relevant parameters for this mode are listed in Table 2.
|Focal plane plate scale||11.86'' mm-1|
|CCD reimaged plate scale||16.60'' mm-1|
|Pixel scale (measured)||0.3988'' pixel-1|
|Field-of-view (CCD)||13.6' x 13.6'|
|Usable field-of-view (diameter)||~15.5'|
|FOV available for multislits||12' x 8'|