Probability distributions for the H-band, J-band and CH₄ short derived ring offsets in RA and Dec for two different MCMC fitting methods. The results from the usual model comparison are shown in black (see Sect. 4.2). The results from the method where the model includes the self-subtraction (Sect. 4.3) undergone by the reduced data are shown in green, blue and orange. The offset of the ring from the stellar position in RA is in good agreement for all filters, except J-band, where it differs by half a NICI pixel (~10 mas). This is because the star was offset by 3–5 pixels from the center of the mask during the J-band observations, which likely led to a systematic error in our centroid estimate.