The University of Hawaii Wide‐Field Imager (UHWFI)

The University of Hawaii Wide‐Field Imager (UHWFI) is a focal compressor system designed to project the full half‐degree field of the UH 2.2 m telescope onto the refurbished UH 8K × 8K CCD camera. The optics use Ohara glasses and are mounted in an oil‐filled cell to minimize light loss and ghost images from the large number of internal lens surfaces. The UHWFI is equipped with a six‐position filter wheel and a rotating sector blade shutter, both driven by stepper motors. The instrument saw first light in 2004 in an engineering mode. After filling the lens cell with index‐matched oil, integrating all software components into the user interface, tuning the CCD performance, and purchasing the final filter set, the UHWFI is now fully commissioned at the UH 2.2 m telescope.