  One of the most dramatic results from the first RHIC run are the STAR results
for pi+- pi+- interferometry. They showed that the ratio of the so-called
R_{out} and R_{sid} radii seem to decrease below unity for increasing
transverse momentum of the pair (K_T). This was subsequently confirmed by
PHENIX, which also extended the K_T range of the measurements. We consider here
the effects of opacity of the nuclei on this ratio, and find that such a small
value is consistent with surface emission from an opaque source.
