Top panel: histogram of the ratio of the fitted half-light radius a to a_sub,1800, the rim radius for a sublimation temperature of 1800 K and no backwarming. The open blocks in the bars have the same meaning as in Fig. 19. One outlier, R CrA is beyond the plot limits with r_norm ≈ 9. Bottom panel: histograms produced from simulated observations and parametric fits to three types of MCFOST models, each for three central star types: A8, A0, and B2.