  Using Magellan/IMACS images covering a 1.2 x 1.2 sq. degree FOV with seeing
of 0.4"-0.6", we have applied convolution techniques to analyse the light
distribution of 364 confirmed globular cluster in the field of NGC 5128 and to
obtain their structural parameters. Combining these parameters with existing
Washington photometry from Harris et al. (2004), we are able to examine the
size difference between metal-poor (blue) and metal-rich (red) globular
clusters. For the first time, this can be addressed on a sample of confirmed
clusters that extends to galactocentric distances about 8 times the effective
radius, R$_{eff}$, of the galaxy. Within 1 R$_{eff}$, red clusters are about
30% smaller on average than blue clusters, in agreement with the vast majority
of extragalactic globular cluster systems studied. As the galactocentric
distance increases, however, this difference becomes negligible. Thus, our
results indicate that the difference in the clusters' effective radii, r$_e$,
could be explained purely by projection effects, with red clusters being more
centrally concentrated than blue ones and an intrinsic r$_e$--R$_{gc}$
dependence, like the one observed for the Galaxy.
