TSI reconstructed with MD1 (left panels) and SF (right panels) Ca II K data as a function of time (a) and difference of TSI reconstructions to the PMOD TSI composite (b–d) when using different approaches to account for the sunspots: using the Mandal et al. (2020) series to get the sunspot filling factors (light blue in panel a and red in panel b); using the Mandal et al. (2020) series to get the sunspot filling factors which were also subtracted from those of faculae (blue in panel a and red in panel c); using full-disc Rome/PSPT red continuum data (red in panel a and d) to get the sunspot filling factors (see Sect. 4.2 for more information). The differences are shown only for the common days in all series. Also shown in panel a is the PMOD TSI composite (black). Thick lines show 81-day running mean values. The right part of the lower panels show the distributions of the differences in bins of 0.05 Wm⁻².