Evolution of the light-echo total-flux in the ST magnitude scale as observed in the F435W (upper panel), F606W (middle panel), and F814W (bottom panel) filters. Dashed curve: observed light curve of V838 Mon. Asterisks: observed light-echo magnitudes (Col. 7 in Table 1). Full curve: best fit of the modelled evolution to the observational points. Parameters of the fit can be found in Table 2 upper rows.