Cyan solid lines in all panels show the histograms of differences between line flux measurements performed on J-PLUS photometry (Sect. 3.1) and on SDSS spectroscopy (Fig. C.1), for the case of J0430. The difference between and is normalised respectively by and by in the left and middle panels. We use the systematic shift of the distributions in the left panel to statistically correct (see Sect. 4.1.2). The spread of the distribution in the middle panel, on the other hand, allows the rescaling of the uncertainty associated with measurements in order to account for residual statistical errors not included in . Section 4.4.4 details how we make use of the corrected and in the computation of the errors associated to our final LFs. Finally, right panel shows that well compares to the spectroscopic measure .