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A well-studied maximal gravitational point lens construction of S. H. Rhieproduces $5n$ images of a light source using $n+1$ deflector masses. Theconstruction arises from a circular, symmetric deflector configuration on $n$masses (producing only $3n+1$ images) by adding a tiny mass in the center ofthe other mass positions (and reducing all the other masses a little bit).  In a recent paper we studied this "image creating effect" from a purelymathematical point of view (S\`ete, Luce & Liesen, Comput. Methods Funct.Theory 15(1):9-35, 2015). Here we discuss a few consequences of our findingsfor gravitational microlensing models. We present a complete characterizationof the effect of adding small masses to these point lens models, with respectto the number of images. In particular, we give several examples of maximallensing models that are different from Rhie's construction and that do notshare its highly symmetric appearance. We give generally applicable conditionsthat allow the construction of maximal point lenses on $n+1$ masses frommaximal lenses on $n$ masses.

Creating images by adding masses to gravitational point lenses