CFHT MOS SIS SPECTROGRAPH PERFORMANCE

Initial results of laboratory and on-sky tests of the new CFHT multi-o bject spectrograph, MOS/SIS, are described. MOS/SIS contains two ways, one of which is primarily intended for imagery and spectroscopy of ma ny tens of objects within a 10' field, while the other utilizes tip/ti lt image stabilization for high spatial resolution imagery and spectro scopy over a 3' field. Data on image quality, transmission, flexure an d stability are presented, as well as a description of the multi-objec t observing performance. This highly integrated system incorporates YA G laser drilling equipment and allows on-line acquisition, aperture ma sk design and fabrication for multi-slit observations with minimum ove rhead. A comprehensive software interface provides observers with a us er-friendly environment and ensures that all operations can be quickly and efficiently controlled by novice users.