[Ifeffit] Amplitude and sigma square

Hi all, Thanks to Professor Pierre, Prof. Segre and Prof. Scott, for make some beautiful comments. One thing i wish to mention here that i have both Fluorescence and Transmission data, with the same model transmission data give Amplitude around 0.72 but Fluorescence gives 0.15, Is this self absorption problem, as prof. Segre suggested. Also i have tried with one shell with N=6 and then 4 and 2 and i got the genuine trend on average under limit of error. But the for N=2 the sigma goes to 0.0001 order while for N=4 it is usual 0.001 order (this both have simultaneously taken in a one fit). Also N=6 gives all variable fine. thanks