Dropsize imaging on the base of the ratio of laser induced fluorescence (LIF) and Mie scattering is frequently used for planar non-intrusive measurement of the Sauter mean diameter (SMD) in sprays. In evaporating sprays, the variation of tracer concentration in the liquid phase influences the measurement. We investigate the systematic effects that occur applying this method in evaporating sprays with tracers of different volatilities. The investigations were carried out in a ethanol-fueled spray flame in a coflow of air. For different fuel tracers the resulting two-dimensional distributions of apparent SMD are presented and compared to a simple evaporation model.