Illustration of the optimal spectrum extraction procedure implemented in JENA.py. The dotted circle around spaxel (i, j) in the middle of the 5 × 5 spaxel field shows exemplary the FWHM of the spatial beam. For each surrounding spaxel, that is (partly) covered by the beam, a factor (e.g. v_i+1,j for spaxel (i + 1, j)) is calculated representing the enclosed volume under the normalised 2D-Gaussian beam. Spaxel (i, j) is replaced by the sum of all beam covered spaxels weighted non-uniformly by their specific volume factors (to see on the right side of the picture) while simultaneously preserving its photometric accuracy.