Schematic of the different grids used in the observational pipeline. The relative sizes of the grids are consistent with respect to each other: there is almost one cell from the MHD simulation grid (full grey lines, left), after rescaling of the box as in OBScustom, in a X-IFU pixel (black dashed lines, left) and there are ∼4 cells of the finer grid (light blue lines, right), refined from the MHD simulation grid within the dotted red square and used for the synthetic observation, in a pixel of X-IFU. For the sake of clarity, the absolute sizes of the grids are however not to scale. For instance, there should be 3168 pixels in X-IFU’s hexagon (in our baseline instrumental configuration) instead of ∼30 on the schema, in which X-IFU border pixels are not squared whereas they should be as well in reality.