  The Wendelstein Observatory of Ludwig Maximilians University of Munich has
recently been upgraded with a modern 2m robotic telescope. One Nasmyth port of
the telescope has been equipped with a wide-field corrector which preserves the
excellent image quality (< 0.8" median seeing) of the site (Hopp et al. 2008)
over a field of view of 0.7 degrees diameter. The available field is imaged by
an optical imager (WWFI, the Wendelstein Wide Field Imager) built around a
customized 2 $\times$ 2 mosaic of 4k $\times$ 4k 15 \mu m e2v CCDs from
Spectral Instruments. This paper provides an overview of the design and the
WWFI's performance. We summarize the system mechanics (including a structural
analysis), the electronics (and its electromagnetic interference (EMI)
protection) and the control software. We discuss in detail detector system
parameters, i.e. gain and readout noise, quantum efficiency as well as charge
transfer efficiency (CTE) and persistent charges. First on sky tests yield
overall good predictability of system throughput based on lab measurements.
