With suitable grating tilts several cameras of different focal lengths can be accessed easily. A description of the telescope and spectrograph follows. While not easy to measure, seeing of 1 arc-sec or slightly better can be obtained. Image jitter of a few tenths of an arc-sec is noticeable in good seeing due to the digital drive.
Wind buffeting can induce considerable image motion.
Acquisition and Guiding - Acquisition and guiding are presently done with an intensified CCD TV camera viewing the slit at all times. A zoom lens on the TV enables a variable slit magnification and field of view. This description is provided for performance information only. The zoom lens but not the TV camera itself is offered with the telescope. The choice of collimator is usually determined by the grating size.