Dependence of the deduced wavelength-dependent half-light radius, r_1/2(λ), on the Einstein radius. The inferred r_1/2(λ) from microlensing simulations are shown as black curves for different values of the Einstein radius, r_E (see the legend). Overlaid are the microlensed-based size estimates for two L_opt, 45 ≃ 1 quasars as well as the predicted SS73 wavelength-dependent disk size (dashed line).