Spatially resolved spectroscopic optical coherence tomography (OCT) has been demonstrated to be a convenient tool for spectral analysis in turbid media. For a full-field OCT configuration using a Mirau objective in the visible range, we found that the effective numerical aperture varies over the field of view, leading to field-dependent spectral shifts in the reconstructed spectra. Interferograms recorded with quasi-monochromatic lights are theoretically fitted with a general Mirau interference formula, and we propose a numerical correction method for white-light spectroscopy. The method is then tested successfully for the measure of the reflectivity of a plane gold sample. (C) 2012 Optical Society of America