$\pm$ 30% for a fixed adopted value $\sigma(2h)$ leads to the change of $M_d$ by +7%, -15%.

To compare the obtained disk masses with the photometric estimates we calculated disk mass-to-light ratios in $B$ band $(M/L_B)_d$. For Sb and later type galaxies where the bulge contribution to the luminosity is low, we neglected the difference between the total and disk luminosity. For Sa—S0 galaxies we have taken into account the contribution of bulge. To do this we took a disk luminosity estimates or disk de-projected surface brightness at $R=2h$ from de-projected radial surface brightness profiles available in the literature. In the absence of such data a disk luminosity was calculated from the total luminosity using bulge-to-disk luminosity ratio $B/D$, average for given morphological type (taken from Graham (2001)): $L_{d}={L_{tot}}/{((B/D)+1)}$. Disk color index was obtained in this case from the total color index: $$(B-V)_{d}=2.5\cdot \lg\left(10^{(0.4\cdot(B-V)_{tot})}-B/T\cdot 10^{(0.4\cdot
(B-V)_{bulge})}\right) \,.$$ Bulge color index $(B-V)_{bulge}$ of early type galaxy was taken to be 0.8, if the total color index of galaxy did not exceed 0.8. Otherwise (for very red galaxies), a color index of a disk was accepted to be equal to the total one.

[ **3. Results**]{}

Surface density and disk mass estimates 