Histogram distributions of the bulge isophotal radius of the LTGs in our sample (panel a), and its normalized values to R_eff and the radius enclosing 80% of its total bulge luminosity (panels b and c, respectively). The dashed vertical line in panel a marks the FWHM of CALIFA DR3 data (2. ^′′ 6). The color coding is identical to that in Fig. 6 and is meant to illustrate the variation of the bulge extent among the three tentatively defined ⟨δμ_9G ⟩ intervals (cf. Sect. 3).