The great challenge is encountered ini photographic measurement, with regard to distinctly distinguishing the particle profiles from the background (continuous phase) in poorly illuminated multiphase reactors. In this work, a novel approach utilizing particle scattering is proposed to enhance the brightness contrast. The theoretical basis of this approach is described in detail. A single particle scattering model based on noncoherent scattering hypothesis is built up to evaluate the scattering property. The quantitative relationships between scattering flux and scattering coefficient/absorption coefficient are established. Furthermore, the partial light fluxes projected onto the focal plane by single particles of different sizes are also calculated. Combined with the particle scattering and dispersion, an optimal particle size of similar to 0.5-1.5 mu m is designated. On this basis, four representative oxide powders are tested as scattering particles, i.e., TiO2, Al2O3, CuO, and SiO2; in addition, the TiO2 particles are found to perform the best, based on the theoretical simulation.