In the long camera spectrographic mode, a grating is placed at the re-imaged pupil, and the diffracted beam is directed into the camera. The gratings are mounted in frames which are in turn are mounted to grating tilt mechanisms. There are four grating mount positions for 154 mm x 206 mm gratings on the carousel. One is reserved for the folding flat and is fixed in angle. The initial grating selection is intended to include the gratings shown in Table 2.
