2D completeness maps of the Euclid NGC 6397 field of view. The maps are derived by dividing the field into a 500 × 500 pixel grid and calculating the recovery fraction of artificial stars within each cell. Columns display results for the VIS I_E (left) and NISP Y_E (right) filters. From top to bottom, the rows correspond to increasingly fainter magnitude intervals: [19.5, 20.0]; [23.0, 23.5]; and [24.5, 25.0]. The colour scale indicates the recovery fraction. The clear radial gradient, particularly evident in the fainter magnitude bins, illustrates the severe impact of stellar crowding and elevated background levels on detection efficiency within the cluster’s inner regions. No quality cuts have been applied.