Faculae map identified in SO/PHI (left) and in SDO/HMI, re-projected to the coordinate system of SO/PHI (right). The upper row shows the area analysed in the study, the lower row shows a magnification of the area marked by the black rectangle on the top. In the magnified view, we also show the area that was identified as sunspot in the SO/PHI observations. We indicate the number of pixels identified as faculae in each figure (853 in SO/PHI, and 2356 in SDO/HMI, representing 2.2% and 6.2% of the pixels in this area, respectively). The data shown here are from 6 September 2021.