Parameters of the fits (Eq. (1)) as a function of μ, derived for ten annuli of equal area for all bright features (black), as well as for the network (blue), and plage (red) separately, for PF (panel a) and PFL^* (panel b). The values shown are the means over the entire sample of data, while the error bars denote the 1σ interval. Results for the network are shown in the middle of the μ interval they represent, while the others are slightly shifted in μ to improve the clarity of the plot. The dotted lines mark the values of the best fit parameters derived in Sect. 3.1.