A series of plots presenting the variation of recovered parameters as a function of redshift for galaxy NGC 4431. The layout is the same as Figs 5 and 6. In this example, both single- and multiband fits fail after redshift ∼0.07. In this case, we believe that is due to our inability to construct an accurate mask beyond this redshift, i.e. SExtractor no longer deblends two neighbouring objects. The output model therefore changes shape and magnitude with redshift.