... Parkes | ... Gravitational microlensing of giant luminous arcs: . ... On closer examination, however, the apparently smooth light in the arcs is actually composed of small discrete sources, namely stars. ... Individual stars are unresolved, and the an image of the source region registers the light from a population of stars, L pop . ... In understanding how microlensing affects the stars in the giant luminous arcs, we can make a simple comparison to gravitational microlensing within the local group....