In this work, laser-induced incandescence (LII) and light scattering measurements are explored as means for the quantitative measurement of soot characteristics in a D.I. Diesel engine. Simultaneous, planar LII and light scattering signals from soot in an ethylene diffusion flame were imaged and calibrated against well-established data from laminar diffusion flame studies. The resulting calibration was transferred to results from an optically-accessible D.I. Diesel engine. Application of light scattering theory to the engine data produced planar images of the soot volume fraction, particle size and number density.