Optical design of a highly segmented wide field spectrograph

A lot of scientific interest around both seeing limited wide field imaging and wide field spectroscopy has been shown in the recent past. Technological difficulties have indeed been identified when proposing classical prime focus corrector for 8 meters class telescopes with Field of View bigger than one degree, because of the huge opto-mechanics and of the very large arrays of detectors required. A new concept, the Smart Fast Camera, has been recently proposed: the idea behind relays on splitting the huge Field of View in smaller portions, each of them re-imaging onto a reasonable size detector a part of the scientific Field of View. In this way, one could think to build a modular instrument, with most of the components identical for each module, with the exception of the field corrector, which is of course radial dependent. In this paper, a further development of this concept, allowing for spectroscopy, is presented, applied to an existing 8 meter class telescope, the Large Binocular Telescope. A preliminary study is traced out, with the aim to find a feasible optical design for such an instrument.