There is a choice of either an f/2.11 camera or an
f/3.96 camera, with focal lengths of 128.1 mm and 240.1 mm
respectively. These cameras provide scales at the detector of
23.25 arcsec mm-1 and 12.40 arcsec mm-1 respectively.
Note that in order to change cameras it is necessary to remove
the detector; thus any change must be scheduled well in advance.