Dust opacities used for the standard disk radiative transfer modelling, with parameters a_min = 0.05 μm, a_max = 3 mm, a_pow = 3.5, and 15% amorphous carbon by volume. The extinction per dust mass is shown in black, absorption in red, and scattering in blue. Results shown with lines for ProDiMo, open symbols for MCMax, and full symbols for MCFOST – all of which agree. The red star represents the value of 3.5 cm²/ g(dust) at 850 μm used by Andrews & Williams (2005) to determine disk masses from sub-mm fluxes.