Integral Field Unit Mode (IFU) The integral field spectrometry will primarily be used for large, extended objects like galaxies. In this mode a 3 × 3 arcsecond field of view is sliced into 0.1 arcsecond bands which are thereafter re-arranged into a long slit. This allows to obtain spatially resolved spectra of large scenes and can be used to measure the motion speed and direction within an extended object.