Top left: probability distribution for the RA offset of the HR 4796 A ring for each of the 5 filters. Right: cumulative probability distribution with the 1σ dispersion in the distributions shown in red. Bottom: same for the Dec offset of the HR 4796 A ring. 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 3−5 pixels offset from the center of the mask during the J-band observations, which likely led to a systematic error in our centroid estimate.