Real versus effective albedo of particles of different sizes. The effective albedo (solid line) is defined here as the fraction of light scattered outside the forward ten degrees times the real albedo, see text (dotted line). The green area denotes the range of wavelengths covered by the HST scattered light images. The small, medium, and large panels correspond to a particle size of 0.08 μm, 0.25 μm, and 2.5 μm.