Images of the CFHTLS-D4 (left), GOODS-South (centre), and Bullet Cluster (right) fields as in the final NB1060 image stacks. The inner and outer black contours on the Bullet Cluster image represent the regions where the gravitational amplification is respectively  ≥ 2.5 (Δm ≤ −1) and  ≥ 1.2 (Δm ≤ −0.2) for a source at redshift z = 7.7.