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Next: Above-the-Slit Viewing Previous: Acquisition TV Up: Telescope Focus and Aperture Viewing Optics

Telescope Secondary Focus

One can now bring the telescope into a near focus by watching the TV image while adjusting the secondary position (done by the telescope operator), although a behind the slit ``knife edge'' test is a little more exact. One may also perform a ``knife edge'' focus from above the slit using the eyepiece on the side of the TV. This is slightly less awkward to carry out. Finally, using the method described in Chapter 6, use a row/column plot to make the final collimator focus adjustment on a star.

Pat Hall - Wed Oct 4 11:02:37 MST 1995