Abstract: | The Cassegrain‐Teleskop‐Kamera (CTK‐II) and the Refraktor‐Teleskop‐Kamera (RTK) are two CCD‐imagers which are operated at the 25 cm Cassegrain and 20cm refractor auxiliary telescopes of the University Observatory Jena. This article describes the main characteristics of these instruments. The properties of the CCD‐detectors, the astrometry, the image quality, and the detection limits of both CCD‐cameras, as well as some results of ongoing observing projects, carried out with these instruments, are presented. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |