Top panel: k-correction as a function of redshift. The gray scale shows the k-corrections from the KCORRECT code, the solid cyan line indicates the median and the other coloured lines show the k-correction as predicted by a range of Bruzual & Charlot (2003) SSP models, for various formation times (different colours) and metallicities (different line-styles) as indicated in the top-left of the figure. Bottom panel: luminosity evolution correction as a function of redshift. For clarity, we only show a few of the Bruzual & Charlot (2003) model predictions. The thick green dot-dot-dashed line shows the correction we have used in this work, which is based on the Z = 0.02 instantaneous-burst model that formed 11 Gyr ago.