This parameter is determined from an overscan-subtracted calibration lamp exposure in LSS mode (taken with the template FORS2_lss_tec_waveLampcheck). The total signal is integrated and normalized by the exposure time and the total number of original CCD pixels (keeping into account possible binning). More information can be found in the plot tutorial.

DB Name: fors2_lamp_chk
TPL.ID: FORS2_lss_tec_waveLampcheck
QC1 DB parameter: flux