Moving-average χ_reduced² value for each galaxy in our sample, plotted as a function of R/R_d, where R_d is the disc scale length. For each galaxy and each dust masking cut-off, we measure χ_reduced² in a 0.5 × R_d bin, spaced in radius along the major axis. χ_reduced² = 1 is represented by a dotted line, and R_d = 0.5 (bulge-dominated region, e.g. Fisher & Drory 2010) and R_d = 2.2 (disc-dominated region, (e.g. Freeman 1970; Persic et al. 1996)) are represented by vertical dashed lines. We also plot in grey the χ_reduced² measure for our E(B − V) ≤ 0.7 model, but applied to E(B − V) ≤ 0.2 bins. Dotted blue lines are plotted at 3.5 kpc for IC 1711 and at 2.5 kpc for NGC 3957, the radius at which their photometric shoulders end (see Sect. 5.2.1). We note that NGC 5775 and NGC 0360 are not perfectly edge-on and show clear spiral arms in their photometry. This explains their strong peaks in χ_reduced². A general trend of decreasing χ_reduced² with mask level is shown, as well as discs fit better than bulges.