In one general aspect, a spectroscopic apparatus is disclosed for investigating heterogeneity of a sample area. The apparatus includes an image acquisition system operative to acquire images of a plurality of sub-areas in the sample area and a sub-area selection interface operative to receive a selection designating one of the sub-areas for which an image has been obtained. A spectrometer has a field of view and is operative to acquire a spectrum of at least part of one of the sub-areas in its field of view, and a positioning mechanism is responsive to the sub-area selection interface and operative to position the field of view of the spectrometer relative to the sample area based on a received selection.