This case study concerns the fluorescence measured from the PAL mutant of a cyanobacterium, which contains only photosystem I (PSI) and photosystem II (PSII). With PSI the difference between open and closed reaction centers (RC) is negligible in the fluorescence, because both the oxidized and reduced RC efficiently quench the excitations. However, with PSII there is a huge difference, with closed RCs exhibiting a huge amount of recombination fluorescence. The measurement and the global analysis are described in (Tian et al. 2013). The target analysis is based upon the model explained in (van Stokkum 2018).