Microlensing probability of magnification for the Spock galaxy. Left: relative probability of magnification in different scenarios where the macromodel tangential magnification (μ_T) or the surface mass density of microlenses (Σ_* expressed in units of M_⊙ pc⁻²) is varied. In all cases, the radial component of the macromodel magnification is fixed to μ_R = 1.63. Different values of the tangential magnification can be interpreted as different distances to the critical curve. At the lowest magnification values considered, the probability of large magnification follows the expected μ⁻² law. For larger values of μ_T, the probability resembles a log-normal. Right: fraction of area in the source plane with magnification factors above a certain value. The models are the same as in the left panel.