Verification of Eq. (1) when applied to real LMC data. The top panel shows stars in the 8_8 tile, in the K_s vs. diagram of VMC. Different colours are used for likely LMC giants (brown), likely Milky Way dwarfs (green), stars bright enough to be partially saturated (cyan), and stars for which 2MASS photometry is not available (black). The bottom panel shows the difference between the Y magnitude as measured from VMC data, and as inferred from 2MASS photometry via the first Eq. (1), as a function of Y, for stars with both VISTA and 2MASS photometry. The vertical dashed lines denote the magnitude interval for which this comparison is the most significant, as discussed in the text.