Th S = ½ AF spin ladder is one of the most important models in quantum magnetism. While its properties throughout the (H,T)-phase diagram may be considered to be well understood now, the effect of non-magnetic impurities remains a challenging task. We propose to study the effect of impurities in the spin-ladder material DIMPY, doped with non-magnetic Zinc. Our previous thermodynamic, neutron scattering and NMR experiments in combination with numerical studies, proved that DIMPY is a perfect Heisenberg spin-ladder. Hereby, we propose to study the real-space shape of emerging 'spin islands' around Zinc ions. Using the LET spectrometer at ISIS, we propose to study the low-energy spectrum at H=2T and in particular, the M_S = -1/2 -> M_S = 1/2 (local) transition of spin-islands. We apply for 3 days of beamtime. A vertical magnet (H<3T) and dilution temperatures are required.