Cassegrain f/8.8 Ritchey-Chretien focus
CCD WHT Camera
Users manual for the White Guider
Kevin Meyer is the McDonald Operations staff member responsible for CCD WHT
guider. The "WHT" camera is the only offset guider available for CCD
imaging. Currently the only CCD available is TK4 (1024x1024, 24 micron
pixels). The offset guider accepts the usual optical-band filters. The
imaging system can also be used in a "high-speed" mode, meaning times
between integrations as short as a few seconds with the actual time
depending on the size of the sub region on the CCD that is readout.
Because the instrument is mounted at the broken Cassegrain focus,
access to the instrument during observations is seldom possible.
Therefore, the observer must rely on the telescope tracking,
with no ability to guide directly. Integration times of up to a
few minutes will produce good images, dependent on location in the
sky and acceptability of smear. In the R band, it is possible to
image down near the sky level in this time.