The spatial characteristics o f a laser plasma Extreme UV continuum source used in absorption spectroscopy was examined. The spectroscopic system consists of a toroidal mirror in series with a 2.2m grazing incidence spectrometer resulting in a quasi-stigmatic imaging system. The experimental knife-edge response of the system was recorded in both the vertical and horizontal directions for energies of 50, 75, 100, 125 and 150eV. Estimates of the spatial resolution of th e system were obtained from the various experimental knife-edge responses of the system using the 25-75% and 10-90% criteria. Using the ray tracing software SHADOW, the system was ray traced for each of the five energies above. The experimental knife-edge experiments in both the vertical and horizontal directions were then simulated in a series of virtual knife-edge experiments. The source size defined in SHADOW was varied until optimal correlation was achieved between the virtual and experimental knife-edge response of the system. The source size that corresponded to best match between the experimental and virtual knife-edge experiments, for the different energies, was then defined in SHADOW and the system was ray traced using this source. The footprint of the rays on two screens, placed at the position of an absorbing plasma, provided estimates of the absorption volume. In any future work, the absorption volume estimates can therefore be used in the measurement of absolute photoabsorption cross-section data.