Top panels: reconstructed images of CL Lac at 1.52 μm (left) and 1.70 μm (right). They are convolved with the interferometric beam and the intensity is normalised between [0, 1]. The contour lines correspond to [0.015,0.05,0.20,0.70,0.95,0.97,0.99]. East is to the left, north is up. The barycentre of a symmetric star would be expected at x = 0 and y = 0, as shown by the blue dashed line. Bottom panel: surface rendering difference between CL Lac images at 1.52 and 1.70 μm.