Calibration tests of the metallicity distribution. In the top panel, the MDF is shown for the all the NGC 5128 stars from I = 27 to 28 from the first panel of the previous figure. In the second panel, the MDF is shown for all the NGC 5128 stars that were recovered in the simulation tests (those in the middle panel of the previous figure). In the third panel, the MDF for these same recovered stars is shown, but now derived from their photometry as actually measured from the simulations (i.e. from the third panel in the previous figure). All three panels are normalized to the same number of stars. The bottom panel shows the ratio of the first and third histograms, normalized to an overall average of 1.00.