Design and performance of a double focus optical telescope

A double-focus optical telescope (DOT) has been built for public observation and scientific research. The unique optical property of the DOT is that, both the Ritchey-Chretien (R-C) and Prime Focus systems are achieved on one telescope, using a common primary mirror. Switching between the R-C and Prime Focus systems is accomplished by moving the secondary mirror away from the optical path. The DOT also provides public observations through the eyepiece system.