Caustics of compensated spherical lens models

We consider compensated spherical lens models and the caustic surfaces they create in the past light cone. Examination of cusp and crossover angles associated with particular source and lens redshifts gives explicit lensing models that confirm the claims of paper I (Ellis et al 1998 Class. Quantum Grav. 15 2345), namely that area distances can differ by substantial factors from angular diameter distances even when averaged over large angular scales. 'Shrinking' in apparent sizes occurs, typically by a factor of 3 for a single spherical lens, on the scale of the cusp caused by the lens; summing over many lenses will still leave a residual effect.