Ratio of the (BCG + ICL)₅₀₋₂₀₀ flux (F_measured) measured by each fitting method to the (BCG + ICL)₅₀₋₂₀₀ flux of the input model (F_in, equivalent to the signal component in our S/N measurements) for varying f_ICL at a fixed halo mass of M_h = 10^14.7 M_⊙. Points are coloured by redshift. The error bars show the standard deviation of all successful measurements of the (BCG + ICL)₅₀₋₂₀₀ flux divided by the (BCG + ICL)₅₀₋₂₀₀ flux of the input model. Alternating points at each mass and f_ICL value have been offset to the right for clarity.